Chop the sweet potato into small bits, and soak them for a while in a heat-resistant dish filled with water, drain and replace the water, wrap in plastic wrap, then microwave for about 5 minutes.
Microwave butter in a separate heat-resistant dish for about 30 seconds to soften.
Preheat the oven to 170℃.
Combine the sweet potatoes and butter with the rest of the ingredients, and mix until evenly combined.
Bake in oven for 40 minutes, then it's done.
Story Behind this Recipe
Since I had some sweet potatoes, I used them in my regular pound cake.
This recipe is low in sugar so that you can enjoy the natural sweetness of the sweet potatoes. For those who prefer a sweeter cake, use about 40 g sugar in place of the kuromitsu. You can also use a milk carton for the pound cake mold. It tastes best the day after baking. I make it the night before, and serve it up for breakfast as a substitute for bread.