In a mixing bowl, mix the flour, baking soda, baking powder, cinnamon, and salt. Using a mixer, beat the butter, brown sugar, and sugar on high for 2 minutes. It should be pale and fluffy. Add the mashed bananas, sour cream, and vanilla. Mix until combined.
1/2 tsp Baking soda, 1 tsp Baking powder, 1 1/2 tsp Ground cinnamon, 1/2 tsp Salt, 1/2 cup Unsalted butter, 1/2 cup Brown sugar, 1/4 cup White granulated sugar, 2 Ripe bananas , 1 tsp Pure vanilla extract, 1/4 cup Sour cream