#HowItsMade Mondays 9/8c on Science This Whoopie Pie factory has a variety of delicious ingredients that give these traditional treats their signature taste.. Beat the butter and sugar in an electric mixer on high speed until light and fluffy. Beat in the egg, followed by the vanilla and buttermilk. Reduce speed to low, add dry ingredients and beat until combined.. 8/31/2009 Classic whoopie pie! The only thing I changed was omitting the egg whites from the filling and adding about 2 Tb. of milk and an extra 1/4 cup of powdered sugar.. You can make everything you want vegan, even whoopie pies, as this recipe will prove. Not quite a pie, not quite a cookie or cake, these fun desserts are somewhere in between and now they're vegan too.. L.D. 71, officially known as "An Act to Designate the Whoopie Pie as the State Dessert", read "The whoopie pie, a baked good made of two chocolate cakes with a creamy frosting between them, is the official state dessert".. Whoopie Pie Recipes Looking for whoopie pie recipes? Allrecipes has more than 20 trusted whoopie pie recipes complete with ratings, reviews and baking tips..