Banana Bread Whoopie Pies with Fluffy Vanilla Bean Frosting Recipe

1. Preheat oven to 350 degrees F.

2. In a mixing bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.

3. In a separate mixing bowl, whisk together mashed banana and sour cream. Set aside.

4. In a large mixing bowl, using an electric hand mixer on medium-high speed, whip together butter, granulated sugar, and light-brown sugar for about 3 to 4 minutes until pale and fluffy.

5. Blend in egg. Add banana mixture and mix until combine. Slowly add dry ingredients and mix just until combined. 

6. Scoop dough by rounded tablespoon fulls (about 1½ tablespoons) and drop onto Silpat or parchment-lined baking sheets placing them about 1½ inches apart, then smooth edges and flatten cookie as needed (diameter of cookie should be about 1½ to 2 inches.)

7. Alternately, fill a pastry bag fitted with a ¼-inch plain tip with batter, then pipe dough into 1½- inch rounds onto a baking sheet. (This method may yield more than 2 dozen pies).  

8. Bake in preheated oven for 12 to 13 minutes until edges are golden.

9. Allow to cool for 2 minutes on the baking sheet, then transfer to a wire rack to cool completely.

10. Spread and sandwich a layer of frosting between two cookies. Store in an airtight container (in the refrigerator if not serving within a few hours).

Vanilla Bean Frosting:

1. In a large mixing bowl, using an electric hand mixer on medium-high speed, whip butter, and vanilla bean seeds for about 4 minutes until pale and fluffy.

2. Add powdered sugar, milk, and vanilla extract and blend for 2 minutes until light and fluffy.