Preheat oven to 350˚F.
Using a stand mixer, whip butter and sugar together. Continue mixing, adding the eggs one by one. Add flour, baking powder, milk, and sour cream, and mix well to combine.
Divide the batter into two equal bowls. Add matcha powder to one bowl, and cocoa powder to the other. Mix well to fully combine the powders into the batter.
Coat a nonstick 9 x 5" loaf baking pan with butter or oil. Place dollops of the matcha batter in the prepared loaf pan, then layer with dollops of the chocolate batter. Continue alternating layers of batter until all batter from each bowl is in the loaf pan. Using a knife, “draw” an 8 through the batter to get a beautifully colored swirl pattern.
Bake for about 60-70 minutes. Let the cake cool down completely and top with chocolate glaze, if desired. Enjoy!
Makes 1 loaf cake
Recipe & photos are courtesy of Alena Haurylik @alenafoodphoto