Preheat the oven to 350 degrees.

In a mixing bowl, combine the ingredients for the cookies, and blend until a smooth dough has formed.

Form the dough into 20 small evenly sized balls, and flatten them slightly with your hands.

Place the cookies onto a parchment lined baking sheet, and bake for 10-15 minutes until cooked through.

Let the cookies cool completely.

While the cookies are cooling, mix together the ingredients for the filling until stiff peaks have formed.

Place a dollop of the filling on top of one cookie, and place another cookie on top of the filling to form a whoopie pie sandwich.