Treat yourself to this super-moist, delicate, and bouncy Japanese sponge cake with a hint of honey! Made with only four ingredients, Castella Cake is a very popular tea-time confection in Japan that makes the perfect holiday or hostess gift, too.

Japanese Castella Cake, or Kasutera (カステラ) in Japanese, is a popular Japanese honey sponge cake that Portuguese merchants originally introduced to the Nagasaki area in the 16th century. The name derives from the Portuguese Pão de Castela, meaning “bread from Castile”. To make Castella, we use just 4 basic ingredients: bread flour, eggs, sugar, and honey.
A dark brown top and bottom crusts with a creamy yellow center give a beautiful contrast to the sponge cake. This delicate cake is very moist, smooth, bouncy, and has just enough sweetness with a fragrance of honey.
The difference between Japanese honey sponge cake and regular western sponge cake is that Japanese Castella is more delicate and bouncy in texture. It is raised solely by egg foam. There is no butter, oil, or any leavening agent like salt or baking powder. It also uses bread flour (higher gluten content) instead of regular flour to achieve the result. The flavor is very light with mild sweetness. Therefore the cake is delightful to enjoy green tea or iced coffee during summertime.
You can tell by its popularity as Castella is being sold everywhere in Japan, from departmental stores, and specialty sweet stores to convenience stores. They often come in a slim rectangle box in simple plastic packaging for an everyday snack or fanciful packaging for gifting.
Traditionally, Japanese Castella cake is baked slowly in a wooden frame to create a soft smooth texture for the sponge. A metal baking pan would transfer the heat too fast and it would become too dry. I assume most of you would not have a wooden frame readily available, so my Castella recipe uses a standard 1-lb loaf pan.
I searched for Castella recipes in Japanese and found hundreds of recipes available online. The majority of them use just the same 4 ingredients with slightly different measurements for each recipe. I started to experiment with measurements for each ingredient for my 1-lb loaf pan. Then I increased to two pans as my family really loves this light and moist Japanese Castella Cake for oyatsu (snack).

Before I move on to the recipe, I want to mention that it took me a very long time to finalize this recipe. Since then, I have been using this exact recipe many times and it worked each time. However, please understand that everyone’s oven works differently and you may need to adjust the recipe according to your oven.
Japanese Castella Cake Baking Notes:
The key to a successful Castella is in the beating of the eggs and baking time. Even after trying many times, I still wish to improve the slightly wrinkled top (Any tips, anyone?). Otherwise, the texture and flavor is just perfect!
Before I realized that I needed to create my own recipe that works for my oven, I had tried many other Castella recipes I found online. However, I failed miserably despite the beautiful pictures shared in those recipes. Here are some of the tips I learned from my experience in achieving the perfect texture:
Failure 1: A hard and dense layer formed at the bottom of the cake although the top layer turned out beautifully.
Tips:
- There needs to be enough air beaten into the batter for the cake to rise. Make sure to beat the eggs based on the time specified. The texture will be thick and the color will be pale yellow. When you stop the mixer and lift the whisk attachment, the mixture should fall into ribbons.
- Sift the flour two times to loosen.
Failure 2: The cake sank in the middle during the baking, or after I pulled it out from the oven.
Tips:
- Bake it longer until the cake is firm and fully cooked inside.
- Do not over-mix the batter when you add the flour mixture.
- Must use bread flour.

A lot of recipes suggested to bake at a higher temperature and covering the cake with aluminum foil to prevent the cake from browning further and finish baking. However, this made the cake start to sink immediately and it didn’t work for me… Therefore, I couldn’t bake at a higher temperature than 320 ºF (160 ºC).
Some recipes suggest baking it at a higher temperature to brown the top first, then changing to a lower temperature to continue baking. But being unable to cover the top with aluminum foil, my only option was to bake at 320 ºF (160 ºC) and slowly brown the top without overcooking inside of the cake.
You may need to tweak my recipe in order to get the perfect result. I have also seen some recipes that require extra steps and ingredients, but I made this recipe as simple as possible without losing authentic flavor. I hope my recipe works for you and you will get to enjoy Castella with your family and friends.
I’ve also included a 3-minute Japanese Castella Cake recipe video above, so I hope you will check it out.

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Japanese Castella Cake
Video
Ingredients
- 1⅔ cup bread flour (weigh your flour or use the “fluff and sprinkle“ method and level it off)
- 2½ Tbsp water (warm)
- ⅓ cup honey
- 6 large eggs (50 g each w/o shell) (at room temperature—very important!)
- 1 cup sugar
For the Honey Syrup
- 1 Tbsp honey
- ½ Tbsp water (warm)
Instructions
- Before You Start: Please note that this recipe requires a resting time of 1 day.I highly encourage you to weigh your ingredients using a kitchen scale for this recipe. Click on the “Metric“ button at the top of the recipe to convert the ingredient measurements to metric. If you‘re using a cup measurement, please follow the “fluff and sprinkle“ method: Fluff your flour with a spoon, sprinkle the flour into your measuring cup, and level it off. Otherwise, you may scoop more flour than you need.
- Gather all the ingredients. Preheat the oven to 320ºF (160ºC). For a convection oven, reduce the oven temperature by 25ºF (15ºC) to 295ºF (145ºC).
- Cut the parchment paper to fit the baking pans (see the video for this process). You will need two loaf pans (8½ x 4½ x 2¾ inches, or 22 x 11 x 7 cm). If your pans are smaller, add the excess batter to another smaller pan and use a shorter bake time.
To Make the Batter
- Sift 1⅔ cup bread flour twice with either a sifter or fine-meshed strainer. Holding the handle of the strainer with one hand and tapping it gently with the other, the flour will gradually sift through the strainer. Tip: Bread flour gives the cake an elastic, bouncy texture that you cannot achieve with all-purpose flour.
- Add 2½ Tbsp water to ⅓ cup honey (5 Tbsp + 1 tsp) and whisk well.
- Fit a stand mixer with the whisk attachment. Crack 6 large eggs (50 g each w/o shell) into the bowl of the mixer and vigorously whisk until combined.
- Add 1 cup sugar.
- Beat the eggs and sugar on high speed (Speed 10) for 5 minutes. If you beat the eggs with a handheld mixer, it will take more time. The beaten eggs will quadruple in volume. The texture will be thick and the color will be pale yellow. When you stop the mixer and lift the whisk attachment, the mixture should fall in ribbons.
- Add the honey mixture into the egg mixture and whisk on low speed (Speed 2) until combined, about 30 seconds.
- Add the bread flour in three parts. Add one-third of the bread flour and whisk at low speed (Speed 2) for 15 seconds. Then, add another third and whisk for another 15 seconds. Finally, add the last remaining portion and whisk until just combined for about 1 minute. Do not overmix.
To Bake
- Spray the loaf pans with oil and distribute it evenly with a pastry brush.
- Put the parchment paper in the pans and make sure the paper sticks to the pans. If is does not, apply more oil to the pan, spread it evenly with a brush, and place the parchment paper again.
- Pour the batter into the pans about 80% full.
- Using a skewer, draw a zigzag line through the batter to remove the air bubbles in the batter.
- Level the batter by holding each pan 2 inches above the counter and dropping it flat onto the counter. Do this several times to release the air bubbles.
- Bake at 320ºF (160ºC) in the middle rack of the oven for 35 to 40 minutes (I bake my cakes for 35 minutes), or until golden brown and a skewer inserted in the center comes out clean. Turn off the oven, at which point I open and leave my oven door ajar for a few minutes. Then, I take out the cakes. When done, the cake sides will pull away from the pan slightly; the top will be flat and feel spongy when pressed with a finger.
To Apply the Syrup and Chill Overnight
- To make the honey syrup, mix 1 Tbsp honey and ½ Tbsp water in a bowl. Immediately apply the honey syrup over the tops of the hot cakes with a pastry brush.
- For each cake, place a sheet of plastic wrap on the countertop. Take out the hot cakes from the pan and place them top down on the plastic wrap. Gently peel off the parchment paper.
- Immediately wrap the cakes with the plastic film to retain moisture. Bring the cake to room temperature. Then, put the wrapped cakes in the refrigerator and store them overnight (or at least 12 hours), keeping the top side facing down. This will help the cakes develop a fine and moist texture.
To Serve
- Remove the cake from the refrigerator. Bring the cake to room temperature. Slice off the four sides of the cake with a sharp bread knife. Then, cut the cake into ¾- to 1-inch-thick slices (you will get 7–8 slices total). Serve it with tea or coffee, if you‘d like.
To Store
- To save for later, wrap individual pieces with plastic wrap. You can store at room temperature for up to 3–4 days, 5–7 days in the refrigerator, and 1 month in the freezer.
I baked this in a glass pan, since I don’t have a metal loaf pan. It took 50 minutes to set in the middle, but that was expected given that glass is a poor conductor relative to metal. The cake has a nice mild egg flavor but is rather dry (I think this might be due to the longer baking time in my glass pan?). The top of the cake is a little soggy. I’m not sure what happened there. I think the sog is a combination of the honey glaze and condensate collection from the upside down rest in the fridge. Maybe I didn’t wrap the cake tightly enough and it allowed condensate to pool at the bottom instead of evenly soaking into the cake.
If I make this again, I would increase the baking temperature to 350 F. The cake didn’t get very brown on the sides or top by the time it was set (again likely because my pan is glass), and a higher temp might allow for a faster bake time with more browning and less moisture loss.
Overall: Nice flavor, bad texture (possibly due to my mistakes).
Hello, Beth. Thank you for experimenting with Nami’s recipe and sharing your findings with us.
Yes. When baked in a metal or wooden frame, this cake will turn out better. Glass and ceramic will conduct heat more slowly, resulting in the results you mentioned.
Dropping the temperature by 25°F and increasing the bake time by 5 to 15 minutes is the best strategy to balance the glass baking.
We hope this helps you in your future attempts or that you try this recipe in the metal pan again. 🙂
Happy Baking!
If I wanted to alter the flavor a bit how might I go about that. I was thinking of making it orange/citrus flavored but wasn’t sure what that would entail.
Hello, Todd! You may add some orange zest to the cake mix. You may also use lemon juice instead of water to blend with the honey.
We hope this helps! Thank you for experimenting with Nami’s recipe!🙂
This cake was delicious! It is a light cake that can be had as a tea time snack or by itself. Would definitely make again! Thanks for a great recipe!
Hi Swati! Thank you so much for trying Nami’s recipe and for your kind feedback!
We are glad to hear you enjoyed Castella Cake! Happy Baking!
I grew up eating カステラ in Japan. Our family was large, so we ate カステラ only on festive days. I sure do miss those days.
Hi William! Thank you for taking the time to read Nami’s post and share your experience with us.
We hope you will give this recipe a try and recreate the memorial flavor soon! 🤗 Happy Baking!
Thanks for the wonderful recipe! Wondering if it is possible to substitute honey with other variation? Love the texture!
Hi MSu! Thank you so much for trying Nami’s recipe and for your kind feedback!
We’re glad you liked the texture.
Honey is an important ingredient in this recipe, and we have never used a substitute before. When using other sweetened products, the texture and flavor may differ.
Brown sugar syrup or vanilla syrup may work, but the flavor will be different.
We hope this helps!
Please let us know how it goes if you experiment with other items!😉
Hello Nami,
I would like to make this cake the traditional way, and my Dad has offered to make me wooden cake boxes! Could you please tell me what the interior dimensions of the wooden loaf boxes should be?
Also do you have any specific guidance for baking with wooden boxes? I know you should always use parchment paper and bake at 150F, but how long?
Thank you!!
Best Regards,
Kendall
Hi Kendall! Thank you for reading Nami’s post and trying her recipe!
How lucky you get to bake this cake in the traditional wooden box! We haven’t tested it yet.
The method requires a little bit of a different technic, and here is the recipe and instruction from a top-rated baking tool company in Japan.
https://www.rakuten.ne.jp/gold/asai-tool/recipe-note/t-284.htm
The recipe is written in Japanese, but we hope you can use the Google translate tool to read it.
Please let us know how this goes!
Love how the cake came out. Very detailed and simple recipe for beginners like me!
Hi Rebecca! Thank you for your generous words on Nami’s recipes. We’re so glad that you enjoy Nami’s detailed instructions!
Happy Baking!😊
Best ever Castella cake! Turned out moist and not overly sweet. I baked in a bundt cake mold and the results were fantastic. It was a huge hit at my mother’s birthday luncheon. She tells me it reminded of her mother’s castella cake; that’s a huge compliment!
Credit belongs to you Namiko ❤
Thank you for sharing your lovely recipes~
Hi Gina! Aww.🥰 Nami and JOC team are so happy to hear you and your family enjoyed the Castella Cake!
Thank you very much for trying Nami’s recipe and for your kind feedback!
Followed this recipe yesterday and I think it came out perfectly. I’ve never had castella before so I don’t have anything ‘official’ to compare it to, but it looks just like the photos. Oh, the one thing I did differently was brush the honey syrup on all sides instead of just the top, since I had plenty left over. After chilling overnight, I let it come up to room temperature before removing the plastic wrap to avoid it sticking. It’s interesting how some comments say it’s too sweet because I would say that it’s much less sweet than conventional yellow cake. These differences might be because honey flavors can actually vary quite a bit, so it will be more or less sweet depending on that. The cake flavor I ended up with is very reminiscent of King’s hawaiian bread, and the texture/crumb is almost more akin to that of a quick bread, which makes sense considering the bread flour.
This was a very easy, straightforward recipe. Nami has never let me down!
Hi Molly! Nami and JOC team are so happy to hear that Nami’s recipe and instructions helped you achieve baking a perfect Castella Cake!
Thank you very much for trying Nami’s recipe and for sharing your detailed cooking experience.
Happy Baking! 🤗
Easy to follow directions however when I tried to remove my cake from the fridge and remove it from the plastic wrap, the top layer (which was face down) came apart so that delicious honey topping was just wasted on the plastic. I did everything as the recipe stated, how else can I prevent this from happening again?
Hi Sue! Thank you very much for trying Nami’s recipe!
We are sorry to hear your cake’s top layer came apart. Nami’s Castella didn’t stick to the plastic wrap. Did you bring the cake to room temperature before removing the plastic wrap? Cutting out the parchment paper and placing it between the cake and plastic wrap might prevent the sticking.
We hope this helps!
I am excited to try this recipe this weekend. If all goes well, I’m thinking of making another to ship to my brother for his birthday. If I ship 2-3 days with some ice, do you think it will hold up? Or better to freeze and ship frozen?
Thanks for this recipe! (I esp appreciated the exact mix speed and times you provided)
Hi Aya! Thank you very much for reading Nami’s post and trying her recipe!
Freeze the cake and ship it with ice might be a better idea, but unsure about the temperature condition of your shipping carrier. To be sure, we recommend getting advice from your carrier.
As a note, this cake can be saved at room temperature for up to 3-4 days, 5-7 days in the refrigerator, or 1 month in the freezer.
We hope this helps!
This was so easy to make and delicious.
Hi A M, Thank you very much for trying Nami’s recipe and for your kind feedback!
We are so happy to hear you enjoyed Castella!🙂
This was so good! I followed the recipe exactly and it turned out perfectly! Made it for my family for Easter dessert and everyone loved it, will definitely make this again. Thank you!
Hi Colleen! Awesome! We are so happy to hear you and everyone enjoyed Castella cake on Easter!
Thank you very much for trying Nami’s recipe and for your kind feedback!
Hi Naomi—I haven’t tried this yet but I can’t wait to. I had this in Japan and only recently realized what it was!
quick question: what’s the benefit of using a loaf pan over, say, a traditional round cake pan? Thank you!
Hi Kayleigh! Thank you very much for reading Nami’s post and trying her recipe!
As Nami mentioned in this post, traditionally, Japanese Castella cake is baked slowly in a wooden frame box to create a soft smooth texture for the sponge.
To duplicate the looks of traditional Castella, Nami uses a loaf pan.
You can bake this cake in the round cake pan if you like. But if you do, please feel free to adjust the baking time, etc, because we only tested in the loaf pan.
We hope this helps!
Thank you kindly for the response!
My pleasure!😊
I found the recipe to be quite sweet, which surprised me for a Japanese recipe, and my husband and kids didn’t particularly care for it, but the steps were very clear and easy to follow which I appreciate. I don’t typically leave reviews but wanted to share that it’s quite sweet if you follow the recipe as-is. If you don’t want it very sweet, I’d recommend cutting out 10% of the sugar (as she’s recommended in comments) and also skipping the step where you brush honey/water on top.
Hi Lana! Thank you very much for trying Nami’s recipe and sharing your experience with us!
We are sorry to hear that this was quite sweet for your family’s taste.
The honey and warm water mixture will add moisture to the Castella Cake, and we strongly recommend not skipping the step. Maybe reduce a bit more sugar in the cake batter for your taste next time?
We hope this works for you.