Preheat the oven at 375F.

In a bowl, mix the flour, baking powder, salt, baking soda. Set aside.

Mix butter with brown sugar and whisk for about 3 minutes.

Add eggs to the mixture one at a time.

Alternatively, add flour mixture and buttermilk. Mix well.

Add mashed banana to the mixture, then add bourbon. Mix well.

Pour batter into bundt pan and bake for 40-45 minutes, or until a wooden toothpick inserted into cake comes out clean. Cool cake for 20 minutes in the pan, then invert onto serving plate.

Chocolate Ganache: combine all the ingredients in the top of a double boiler over simmering water until smooth and warm, stirring occasionally.

Pour the ganache over the cooled cake. Let the cake stand until the glaze is set, at least 30 minutes, before serving.