Gather all the ingredients.
To serve, slice off the sides of the cake with a sharp bread knife and cut into 3/4 to 1 inch thick slices (you get 7-8 slices total). It's better if you bring the cake to room temperature before serving. 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 refrigerator, and 1 month in freezer.
Bread Flour: Castella has a little elastic bouncy texture from bread flour and all-purpose flour cannot achieve this texture.
Beating Eggs: If you beat the eggs with a handheld mixer, it will take more than 5 minutes. Also, if you have a stand mixer Water Jacket (hot water bath), use it for 1 minute while you whisk eggs and sugar. It helps with making a smooth texture for sponge cake. If you use handheld mixer, put the mixing bowl over hot water and whisk for 1 minute.
Baking Time: For our oven, the cake comes out perfectly after 35 minutes. However, each oven works differently and you will need to experiment with your own oven and adjust accordingly. It took me a few attempts to learn the right baking time and temperature.
Equipment you will need:
Recipe by Namiko Chen of Just One Cookbook. All images and content on this site are copyright protected. Please do not use my images without my permission. If you’d like to share this recipe on your site, please re-write the recipe in your own words and link to this post as the original source. Thank you.