Line a standard 12-cup muffin pan with paper liners
In a medium bowl, whisk together flour, sugar, baking powder, baking soda, and salt
Make a well in center of flour mixture
In the well, mix together the butter, mashed bananas, eggs, and vanilla
Stir to incorporate flour mixture, being sure not to over mix
Spoon batter into muffin cups
Bake for 25 to 30 minutes, or until a toothpick inserted in center of a cupcake comes out clean Remove cupcakes from pan; cool completely on a wire rack
Cream Cheese Frosting
In the bowl of an electric mixer, beat the butter and cream cheese until smooth. Slowly add the powdered sugar and mix until everything is combined