Butter ~Brown Sugar Vanilla Extract ~ Egg ~ Cake Flour Very Ripe Bananas ~ Sour Milk Baking Powder ~ Baking Soda Confectioners' Sugar
Preheat oven to 350°F. Spray an 8-inch square pan with non-stick cooking spray with flour, like Baker's Joy.
In a bowl whisk together flour, baking powder, baking soda, and salt.
In a second bowl beat together butter, sugar, and vanilla extract, until light and fluffy (approximately 3 – 5 minutes). Then add the egg and the mashed bananas beating to mix.
To the butter mixture, add the dry ingredients alternately with the sour milk, starting on low, beat until incorporated, then beat on medium-high until smooth.
Pour into the prepared pan and bake for approximately 30-35 minutes or until a cake tester comes out clean.