Position a rack in the center of the oven and preheat to 375°F. Line 18 muffin cups with paper liners.
Sift together flour, baking powder, soda and salt. Beat the butter and sugar together until creamy, then add the eggs and beat until light and fluffy.
Add the bananas and beat until smooth. Add the extracts and buttermilk and combine well. Add the flour mixture, about 1/2 cup at a time, beating until smooth after each addition.
Spoon the batter into the paper-lined muffin cups and bake for 18 to 20 minutes, or until the tops of the cupcakes spring back readily when touched and a toothpick inserted in the center comes out clean. Cool in the pan for about 10 minutes, then remove the cupcakes and allow them to cool completely on a wire rack.
While the cupcakes cool, place the cream cheese, butter, cinnamon, vanilla extract, rum and confectioners' sugar in a large mixing bowl. Beat at medium-high speed with an electric mixer until smooth and creamy. Refrigerate for 10 minutes before frosting the cooled cupcakes.
Store cupcakes in the refrigerator and bring to room temperature before serving (about 10 minutes out of the fridge).
Notes
Note:
For a non-alcoholic version, substitute rum extract for the spiced rum in the frosting.