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.
½ teaspoon Baking soda, 1 teaspoon Baking powder, 1 ½ teaspoon Ground cinnamon, ½ teaspoon Salt, ½ cup Unsalted butter, ½ cup Brown sugar, ¼ cup White granulated sugar, 2 Ripe bananas, 1 teaspoon Pure vanilla extract, ¼ cup Sour cream