I recently saw a suggestion to use a Whoopie Pie cookie to make ice cream sandwiches. It worked out pretty well. This one is adapted from Cooking Light.
1 cup sugar
5 tbs softened butter
1 tsp vanilla
2 large eggs
2 cups all-purpose flour
5 tbs unsweetened cocoa powder
1 tsp salt
1 tsp baking powder
1 tsp baking soda
1 cup buttermilk
Preheat the oven to 375F. Beat sugar and butter together until well-blended (about 2 minutes). Add vanilla and eggs and beat until combined. In another bowl, mix flour, cocoa powder, salt, baking powder and soda together with a whisk. With the mixer running, add flour mixture and buttermilk alternately to the sugar mixture, starting and ending with the flour.
Drop dough by rounded tablespoons, 2 inches apart, on baking sheets lined with parchment or Silpat mats (or sprayed with cooking spray). Bake for 10 minutes or until set. Cool on pan for 5 minutes, then let cool completely on a wire rack. Put the cookies in the fridge for a bit – chilling them will help the ice cream from melting and not sticking to the cookies.
Soften some ice cream. If the brand you’re using isn’t as fluffy as you’d like for ice cream sandwich filling, you can fold in some whipping topping (about 1 carton of it for a 1/2 gallon of ice cream).
The quick and messy way to fill the sandwiches is to just scoop the ice cream on to the cookies. If the ice cream has gotten too soft, put it in the freezer until it’s a consistency you can work with. The fussy way is to line a baking pan with plastic wrap, spread the ice cream to whatever thickness you prefer, and freeze it. When it’s solid, use a cookie or biscuit cutter to cut rounds of ice cream to fill the sandwiches.