For the batter and a 24 cm-in-diameter springform pan: 320 g of all-purpose flour 90 g of cocoa powder 250 g of sugar 150 g of butter 150 g of sour cream 2 large eggs 230 ml of milk 1 tsp of . 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.. Fall in love with this easy recipe for whoopie pies. Two light discs of chocolate sponge sandwich a fluffy vanilla buttercream filling. Perfect for cake sales, packed lunch treats or making friends at the office!. – To assemble the whoopie pies, pipe some of the cream filling on the underside of a football shaped cake cookie. – Place another football cake cookie over the frosting and press down a little to sandwich the frosting between the two cakes.. 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".. Put the top whoopie pie on top of the frosted whoopie pie. 6. Pipe frosting lines on top of the whoopie pies to make it look like football stitching. .