To begin, preheat your oven to 350 and line two muffin tins with 16 cupcake liners. Spray your cupcake liners with non-stick spray.

To a large mixing bowl, add your butter and sugar and beat together with a hand mixer till creamy. Add your banana and beat into the mixture till smooth. Next, add your buttermilk, vanilla and eggs and mix together till just combined.

To the same bowl, add your flour, baking powder and salt and mix together till you have a smooth cupcake batter. Do not over mix.

Fill each cupcake liner about 2/3 way full with cupcake batter, or till all of the batter has been evenly divided among 16 cupcake liners. Bake in the oven for 17-20 minutes, or till the tops are springy to touch and a toothpick inserted comes out clean.

Let cool entirely before frosting.

To a large mixing bowl, add your butter, powdered sugar, and two tablespoons of milk. Place a fine mesh strainer over your bowl, and add your cocoa powder to it. Gently shake back and forth till all of the cocoa powder has filtered through, and the clumps are left in the strainer. Remove the strainer. Beat with a mixer together till creamy. If too thick, add 1-2 more tablespoons of milk, till it reaches your desired consistency.

Pipe or spread on top of your cupcakes. Devour!