Adapted from Baked Explorations
1 3/4 cups cake flour
2 teaspoons baking powder
1 teaspoon salt
1/2 teaspoon cinnamon
1 1/4 stick or 10 tablespoons or 5 ounces unsalted butter, room temperature
3/4 cup granulated sugar
1/2 cup packed light brown sugar
3 large eggs
1 cup sour cream
Confectioners’ sugar to sprinkle on top
1. Preheat oven to 350°F. Line a 9-inch square cake pan with parchment paper and butter the sides and bottom of the parchment paper.
2. Sift together flour, baking powder, salt and cinnamon. Set aside.
3. In a stand mixer, beat butter and sugars together until light and fluffy. Scrape down the bowl. Add eggs one at a time and mix until blended. Scrape down the bowl again.
4. Add the flour in three batches, alternating with scoops of the sour cream. The last addition should be flour. Scrape down the bottom and sides of the bowl and mix a few more times to incorporate but don’t overmix.
5. Pour batter into pan and bake 35-40 minutes, until a toothpick comes out clean. Allow cake to cool at least 20 minutes on a wire rack. Invert and let cool completely.
6. Once cool, sprinkle top with confectioners’ sugar and serve.