Whoopie Pies:

Preheat oven to 350° F / 175° C.

Line one large baking sheet, or two medium-size sheets, with parchment paper, and set aside.

In a large mixing bowl, combine flour, sugars, baking soda, baking powder, cinnamon, nutmeg, and salt.

In a separate mixing bowl, or the bowl of a stand mixer, add mashed bananas, butter, sour cream, egg, and vanilla bean paste, and beat on high speed for two minutes, or until well-combined.

Gradually add dry mixture to wet ingredients, beating well after each addition.

Add chocolate chips or chopped chocolate to batter, stirring gently to combine.

Transfer batter to a large piping bag, and pipe onto parchment-lined tray in 2″ (5 cm) round circles. Be careful to leave about 2″ of space in between each pie, as they will spread while baking.

Dust each pie with a sprinkle of sugar.

Bake in preheated oven for 12-14 minutes, or until just golden brown. Remove tray from oven and transfer to a cooling rack, allowing pies to cool completely before removing from the parchment, and before proceeding to the next step.

Frosting:

While pies are cooling, prepare the frosting: Combine butter, cream cheese, vanilla bean paste, and cinnamon in a mixing bowl (or the bowl of a stand mixer) and whip on high speed until light and fluffy.

Gradually add the confectioner’s sugar, beating well after each addition. The ideal frosting should be fluffy, smooth, and creamy, but not runny. If necessary, add more confectioner’s sugar, a few spoonfuls at a time, until desired consistency is achieved.

Use a spatula to spread a layer of frosting onto the flat side of half of the whoopie pies.

To finish, place a second pie on top of the frosting layer to create a “sandwich.”

Store whoopie pies in an airtight container at room temperature, or in the refrigerator if not serving that day. These will keep in the fridge for 3-4 days, or they also freeze well.