Shamrock Whoopie Pies, This St Patrick's Day version includes a light spearmint flavoring into the frosting sandwiched between vanilla cake tinted gree
Preheat oven to 350° F. Line baking sheets with parchment or a silicone baking sheet, like Silpat, and set aside. In medium bowl combine flour, baking soda, and salt and set aside.
In a large mixing bowl, beat butter on medium to high 30 seconds. Beat in brown sugar until light and fluffy. Beat in egg and vanilla. Alternately add flour mixture and buttermilk, beating after each addition just until combined. Stir in food coloring.
Spoon batter in 2-inch diameter rounds, onto prepared baking sheets, allowing 2 inches between each round for spreading.
Bake 9 to 11 minutes, or until tops are set. Cool completely on baking sheets on rack. Remove cooled cookies from baking sheets.
Meanwhile, cream the butter in a large bowl. Slowly add the powdered sugar and spearmint extract. If the frosting is too thick, thin it with a little milk.
To fill, dollop Whoopie Pie Filling onto the underside of each piece of cake. Top with another cake round.