01 - Preheat your oven to 350°F and line a 12-cup muffin tin with cupcake liners.
02 - In a large bowl, whisk together flour, baking powder, and salt; set aside.
03 - In a separate bowl, beat the butter and sugar until light and fluffy. Add the mashed bananas and mix until combined.
04 - Beat in the eggs one at a time, then stir in the vanilla extract.
05 - Gradually add the dry ingredients to the banana mixture, alternating with milk; mix just until combined.
06 - Divide the batter evenly among the cupcake liners, filling each about 2/3 full.
07 - Bake for 16 to 18 minutes, or until a toothpick inserted into the center comes out clean. Cool completely on a wire rack.
08 - Beat the butter until fluffy, then add powdered sugar gradually. Mix in banana milk or regular milk and vanilla. If desired, blend in extra mashed banana for a stronger flavor.
09 - Pipe or spread the frosting onto cooled cupcakes. Garnish with whipped cream, a maraschino cherry, and a straw for a milkshake look.