⅓cupDark cocoa powder (regular cocoa powder would also workbut the cookies will be lighter and have less of a dark chocolate taste)
1tspbaking powder
½tspbaking soda
½tspsalt
1cupmilk
Mint Filling
½cupbuttersoftened, 1 stick
¼cupshortening
1 ½tsppeppermint extract (not "mint" extractwhich is a spearmint/peppermint combination)
4cupspowdered sugar
¼cupheavy cream
4-5drops green food coloringoptional
1 ½cupsemisweet chocolate chipsI used a combination of mini and regular-sized
Instructions
Cookies
Preheat oven to 450F and line cookie sheet with parchment paper.
In stand mixer (or in large bowl using hand mixer) beat together sugar and butter.
Beat in egg until well-combined, and then stir in vanilla extract.
In separate bowl, combine flour, cocoa powder, baking powder, baking soda and salt.
Measure out milk and set aside.
Starting with flour-mixture, gradually stir flour mixture and milk into batter, alternating (add about ⅕ of dry mix, as soon as ingredients are combined stir in approximately ⅕ of the milk, and repeat until all ingredients are combined). Batter will be fairly runny.
Drop batter by 1-1 ½" spoonfuls onto prepared cookie sheet, spacing at least 1 ½" apart.
Bake 5 minutes, remove from oven and allow to cool completely on cookie sheets before filing.
Filling
In stand mixer (or in large bowl using hand mixer), cream together butter and shortening Stir in peppermint extract.
Gradually add in powdered sugar, pausing occasionally to scrape down the sides of the bowl to ensure all ingredients are well-combined.
Stir in heavy cream and beat on high for 1 minute.
Stir in food coloring until desired color is attained and color is evenly distributed.
Stir in chocolate chips.
Pair together cooled cookies by similar size. Spread frosting over the bottom of a cookie and sandwich with another cookie (i used about 1 ½ - 2 Tbsp filling per whoopie pie). Repeat until all cookies/filling are used and serve.