Preheat oven to 180 C / Gas 4. Grease baking trays. Sift together the 250g flour, bicarbonate of soda,1/4 teaspoon salt, cocoa and 200g sugar.. 496 results for whoopie pie Save whoopie pie to get e-mail alerts and updates on your eBay Feed. Unfollow whoopie pie to stop getting updates on your eBay feed.. 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.. #HowItsMade Mondays 9/8c on Science This Whoopie Pie factory has a variety of delicious ingredients that give these traditional treats their signature taste.. . .