Cut the sweet potatoes into bite-sized pieces and soak in water to remove the bitterness.
Put the drained sweet potatoes in a heatproof dish, add the water, wrap with plastic wrap, and microwave at 600 W for 8-11 minutes.
Use a fork to mash Step 2. While still hot, add the margarine and sugar and mix well.
Add the egg yolk and heavy cream, mixing well with each addition.
Scoop Step 4 into aluminum cups with a spoon, brush with egg yolk, sprinkle the tops with black sesame seeds, and bake in the toaster oven for 8-10 minutes.
It's also delicious if your sweet potatoes are a little lumpy. Keep an eye on them as they bake and bake until the tops brown.
If you want to make a lower calorie version, you can make it without the egg yolks. You can also use milk instead of heavy cream.
If you pour it into a tart crust, it makes a sweet potato tart! Recipe ID: 674825.
Sweet Potato Cakes Recipe ID: 665767
Sweet Potato Pie Recipe ID: 675709.
Story Behind this Recipe
This is a simple sweet potato cake that I've made since my children were small. It's a sweet I came up with as I went. Ogre Dumplings Recipe ID: 650560. Sweet Potato Yokan Recipe ID: 661896.
It's okay if you don't add any milk when boiling, but in that case, add 100 ml of water so that they will soften. Once boiled, throw out the water. Adjust the amount of sugar according to the sweetness of your sweet potatoes.