Banana Cupcakes with Peanut Butter Frosting

Preheat the oven to 350°F (175°C). In a medium bowl, mash the bananas. In a separate bowl, whisk together the flour, baking powder, and salt. In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla extract. Gradually mix in the dry ingredients, alternating with the milk. Fold in the mashed bananas. Spoon the batter into cupcake liners, filling each about 2/3 full. Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Allow the cupcakes to cool completely. In a medium bowl, beat together the peanut butter, powdered sugar, and heavy cream until smooth and creamy. Frost the cooled cupcakes with the peanut butter frosting. Let the frosting set for about 30 minutes before serving.