Find great deals on eBay for whoopie pie. Shop with confidence.. Bake in the preheated oven for 10 to 12 minutes. Let cakes cool then make sandwiches from two cakes filled with the filling. To Make Whoopie Pie Filling: Beat egg white and mix with the milk, 1 teaspoon vanilla and 125g of the icing sugar. Mix well then beat in the butter and the remaining sugar. Beat until light and fluffy. Pumpkin. To cook the pumpkin, either bake or steam it, then peel and . Heat oven to 180C/160C fan/gas 4 and line baking trays with parchment. Mix flour, cocoa, bicarb, sugar and a pinch of salt. Whisk the egg, oil and buttermilk together, then mix into dry ingredients with 75ml boiling water.. The Internet is abuzz with recipes and stories of whoopie pie folklore, while customers everywhere are descending on bakeries in droves demanding these delectable treats. This adorable volume . Chocolate whoopie pies are an American favourite that you can now create at home with this easy to follow, delicious and simple recipe from Jamie Oliver.. While considered a New England classic and a Pennsylvania Amish tradition, they are increasingly sold throughout the United States. The whoopie pie is the official state treat of Maine (not to be confused with the official state dessert, which is blueberry pie)..