Bring the butter to room temperature, then mix it well with the butter until pale and fluffy.
Bring the eggs to room temperature. Beat the eggs and mix them into Step 1 one at a time. Add the almond flour and anko and mix.
In a separate bowl, mix together the rice flour, matcha, and baking powder. Add to Step 2 and mix until no longer powdery. Add the kuromame and mix quickly.
Lightly grease the pound cake pan with butter (amount separate from listed ingredients), then pour the batter into it. Smooth the surface, then bake at 200℃ for 8 minutes. Then, reduce the heat to 180℃ and bake for an additional 15-20 minutes.
Story Behind this Recipe
When I make simmered adzuki beans, I always make this cake. After the New Year's holidays, I have leftover kuromame, so I also add them to the batter.
Once baked, remove from the pan while still warm and wrap tightly with plastic wrap. It's delicious while still warm, but if you let it cool while wrapped and wait a day or two, it's incredibly delicious.