120g full fat soft cheese (cream cheese), at room temperature
70g unsalted butter, room temperature
60g icing sugar
Finely grated zest from 1 lime
3tsp lime juice
Preheat the oven to 180C/ Gas4/ 325F.
Sieve the flour, bicarbonate soda, salt, cocoa and sugar into a bowl.
Crack the egg into a bowl and add the oil, vanilla paste and milk. Whisk lightly and gradually add the remaining whoopie pie ingredients.
Line two baking trays with baking paper. Scoop up a level tablespoon of the mixture and drop gently onto the baking sheet. Repeat until all the mixture is gone, leaving 2cm gaps between each circle. You should have enough to make 24 in total.
Cook the pies for about 10 minutes, then remove from the oven and leave to cool.
For the filling, mix the milk and flour together trying to avoid lumps, and heat in a small pan over a medium heat until a thick paste. Remove from the heat and set aside.