classic whoopie pie recipe

INGREDIENTS

• 125g unsalted butter or vegetable shortening such as Trex, softened
• 200g dark soft brown sugar
• 1 large egg
• 1 tsp vanilla extract
• 280g self-raising flour
• 40g cocoa powder
• 1 tsp baking powder
• ½ tsp salt
• 125ml buttermilk
• 125ml soured cream
• 100ml hot (not boiling) water

For the marshmallow fluff filling

• 200g marshmallow fluff
• 125g unsalted butter, softened
• 200g icing sugar
• 1 tsp vanilla extract
• 50ml milk

Method

1. To start, you will need 2 lightly greased 12-hole whoopie pie tins or a baking tray lined with greaseproof paper. Preheat the oven to 180ºC/gas mark 4.
2. To make the pies, cream together the butter and brown sugar in a mixing bowl for 2–3 minutes using an electric hand-held mixer, until light and creamy. Add the egg and vanilla extract and mix again. Sieve the flour, cocoa and baking powder into the bowl and add the salt, buttermilk and soured cream. Whisk again until everything is incorporated. Add the hot water and whisk into the mixture.
3. Put a large spoonful of mixture into each hole in the prepared tins, or spoon or pipe 24 mounds onto the prepared baking tray. Leave to stand for 10 minutes then bake each tin in the preheated oven for 10–12 minutes. Remove the pies from the oven, let cool slightly then turn out onto a wire rack to cool completely.
4. To make the filling, whisk together the marshmallow fluff and butter in a mixing bowl using an electric hand-held mixer. Sift in the icing sugar, add the vanilla extract and milk and whisk again for about 3–5 minutes, until light and creamy. Spoon the filling into a piping bag fitted with a large star-shaped nozzle and pipe a generous swirl of filling onto 12 of the whoopie pie halves. If you do not have a piping bag, spread the filling over the pie halves with a round-bladed knife. Top with the remaining pie halves and your whoopie pies are ready to enjoy.

source : here