Heat the oven to 350 F and line two 12-cup muffin tins with cupcake liners.

Combine the flour, baking powder, baking soda, and salt in a bowl and set aside.

In a mixing bowl with an electric mixer on medium-high speed, beat the butter and sugar until light and fluffy.

Add the eggs, one at a time, beating well after each addition. Beat in the vanilla extract.

Combine the banana and buttermilk in a cup or bowl.

Beat in 1/3 of the flour mixture, then half of the banana and buttermilk mixture. Repeat with another 1/3 of the flour and the remaining banana and buttermilk mixture, then add the remaining flour and beat until well blended.

Spoon the batter into the prepared muffin tins, filling them about 1/2 full.

Bake the cupcakes for 18 to 24 minutes, until a wooden toothpick inserted into a cupcakes comes out clean.

Cool on a rack and enjoy with powdered sugar or icing.