A whoopie pie is a sweet baked item which is a cross between a soft biscuit, a cake and a pie. It is made up of two round pieces of cake-like biscuits (cookies) which are sandwiched together with a sweet, creamy filling. Other names given to these sweet delights have included hucklebucks, gobs and BFOs (big fat Oreos).. 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.. 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!. 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.. 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.. Ever heard of a whoopie pie? They're a bit like a macaroon but with a more cake-like texture. Hugely popular Stateside, the name comes from when Amish women would put them in farmers' lunchboxes and they'd supposedly shout 'whoopie' if they found one in their box!.