When the fall season rolls in, this twice-baked Japanese Sweet Potato dessert brings a nostalgic memory to many Japanese. We mash the baked flesh and broil it in its own shell for a unique presentation. Sweet and creamy, it makes a delicious autumn dessert or snack.
Prep Time30 minutesmins
Cook Time1 hourhr15 minutesmins
Total Time1 hourhr45 minutesmins
Course: Dessert
Cuisine: Japanese
Keyword: baked sweet potato, sweet potato
Servings: 6Japanese sweet potatoes
Calories: 260kcal
Author: Namiko Chen
Ingredients
3Japanese sweet potatoes (Satsumaimo)(1.8 lb, 816 g; be sure to weigh the potatoes to determine how much sugar and cream to use; select medium potatoes for a nice size shell; avoid small potatoes, which easily break when removing the flesh)
2Tbspunsalted butter
5Tbspsugar(to keep the sweet potatoes natural yellow color, use granulated sugar instead of other sugars such as brown sugar)
2large egg yolks
⅓cupheavy (whipping) cream(you can use milk instead for a lighter version, but I like the rich taste heavy cream gives to this dessert)
½tsppure vanilla extract
1large egg yolk(the egg yolk acts as a binder as well as additional rich yellow color and custardy taste)
Gather all the ingredients. Preheat the oven to 375ºF (190ºC). For a convection oven, reduce cooking temperature by 25ºF (15ºC).
Wash 3 Japanese sweet potatoes (Satsumaimo) carefully (the skin is edible and very nutritious) under running water. Pat dry with a paper towel.
Wrap each sweet potato with a sheet of aluminum foil. Poke a few holes in the potatoes with a skewer (for steam to escape).
Put the sweet potatoes in the oven and bake for 50–60 minutes, or until the inserted skewer goes through all the way.
Carefully open the aluminum foil and cut the sweet potato in half lengthwise. Make sure not to tear the skin.
While it’s hot, scoop out the flesh with a spoon, leaving a ¼-inch (5-mm) wall around the edges to create a shell. We use the shells to stuff the sweet potato pureé later on, so be careful not to break the wall. You will only use the 5 best-looking shells out of 6.
Transfer the sweet potato flesh onto a fine-mesh sieve and strain the flesh by pressing it with a wooden spatula. Alternatively, you can put the flesh in a food processor and make a pureé (you may need to add a tiny bit of water if the sweet potato flesh is too dense).
Continue with the rest of the sweet potatoes. Collect the strained pureéd sweet potato in a bowl.
In a medium saucepan, heat 2 Tbsp unsalted butter over medium-low heat. Once the butter is completely melted, add the pureéd sweet potato.
Add 5 Tbsp sugar and mix well together.
Then, add 2 large egg yolks one at a time and quickly incorporate into the sweet potato mixture so the egg doesn’t become cooked and scrambled. Keep stirring.
Gradually add ⅓ cup heavy (whipping) cream, stirring continuously, and combine well with the mixture.
Add ½ tsp pure vanilla extract and mix until the mixture is smooth and creamy. If the mixture turns into a big lump and not the silky texture, you can add more melted butter and/or heavy cream to loosen up. Turn off the heat.
Scoop the mixture into the sweet potato shells. I use a cookie dough scooper to make the job easier (this is great for portion control, too).
Using an offset spatula (or a silicone spatula), smooth out the surface of the filling, creating a gentle slope in the center of the sweet potatoes.
Place the sweet potato shells on a baking sheet lined with a sheet of parchment paper.
In a small bowl, whisk 1 large egg yolk and brush the egg wash on the sweet potato mixture.
Sprinkle ½ tsp toasted black sesame seeds on the center of each sweet potato.
Position the rack in the middle of the oven. Broil on Medium (500ºF/250ºC) for 3–4 minutes, or until the top starts to brown a little bit.