Sugar Cookie Sandwiches

Directions

1. 1
   To make the cookies, preheat the oven to 375 F and line a baking sheet with a silicone baking mat or parchment paper. Set aside.
2. 2
   In a medium-sized bowl, sift together the flour, cornstarch, baking soda and salt. Set aside.
3. 3
   In a separate bowl, cream together the butter and the sugar. Add in the vanilla extract and egg and beat until combined. Add in the flour mixture about 1 cup at a time, and combine completely after each addition. Fold in the sprinkles and stir once or twice to incorporate, no more than that or else the color will bleed into the dough.
4. 4
   Scoop the cookie dough (try to make them the same size) onto the prepared baking sheet, setting the cookies about 1 inch apart. Bake for about 12 minutes, checking often. Remove them from the oven once the outside edges are just starting to turn a golden brown. Remove immediately from oven at this point and allow to cool on the pan for 5 minutes. Allow to finish cooling on a wire rack.
5. 5
   To make the icing, combine butter and vegetable shortening in a large mixing bowl until creamy. Add vanilla extract and salt.
6. 6
   Add the confectioners' sugar one cup at a time and incorporate completely after each addition. The icing will appear dry after adding all of the sugar. Add the meringue powder.
7. 7
   Add milk and beat until light and fluffy, about 8 to 10 minutes. Scoop into piping bag affixed with desired tip and add water as necessary to make the icing easy to pipe.
8. 8
   To assemble, pair up the cookies by size. Pipe or spoon icing onto the bottom of one cookie and sandwich together with the second, same size cookie.
9. 9
   Cookies adapted from TastyKitchen member Julia Mestas who adapted it from Yammie's Noshery's Funfetti Whoopie Pies recipe.