Shamrock Whoopie Pies

In a large mixing bowl, stir the shortening, sugar, egg and vanilla together using a wooden spoon. In a medium mixing bowl, combine the flour, cocoa, baking soda and salt. Alternate adding the 1/3 of the flour mixture and a 1/2 cup of milk to the shortening mixture. You want to begin and end by adding the flour mixture. Use 2 soup spoons to drop the batter onto an ungreased baking sheet. Leave 1-inch between each cake. Bake at 375° for 10-12 minutes Place the cakes on a wire rack. Cool completely, about 30 minutes While the cakes are cooling, prepare the filling In a medium mixing bowl, combine the shortening, confectioners’ sugar, fluff and mint The batter should be light and fluffy. If it is too thick, add evaporated milk 1 teaspoon at a time to thin Once batter is desired consistency, add green food coloring if desired Match the cakes into pairs by size Drop 2 Tablespoons of filling onto the center of one of the cakes in each pair Use a knife to smooth out the filling Place the second cake over the filling