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. Spoon 20 spoonfuls onto trays, well spaced. Bake for 12 mins or until firm to touch, peel off trays. Cool.. Mix together and spoon into a 12 cavity whoopie pie pan that is sprayed with non stick spray. Cook 10 min in 350 degree oven For filling 5 tbsp of cool whip 2 tbsp Marshmallow Fluff Mix together . 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 . #HowItsMade Mondays 9/8c on Science This Whoopie Pie factory has a variety of delicious ingredients that give these traditional treats their signature taste.. 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.. 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..