Whoopie Pies with Peanut Butter and Marshmallow Cream

For the cakes

• Heat the oven to 180°C (160° fan)  gas 4.
• Line 3 large baking trays with non-stick baking paper.
• Beat the butter and sugar in a mixing bowl until light and fluffy.
• Gradually beat in the egg until blended.
• Sift in the flour, bicarbonate of soda and salt and gently stir in, until incorporated. Stir in the buttermilk until smooth and thick -you may not need all the buttermilk.
• Drop 2 tablespoons of the mixture at a time onto the baking trays, keeping them about 4 cm|2" apart. 5 Bake for 10-15 minutes, until cooked through.
• Insert a skewer into the centre - it should come out clean.
• Cool on the baking trays for a few minutes, then place on a wire rack to cool completely.

For the peanut buttercream

• Beat the butter and peanut butter with an electric whisk until smooth.
• Add the icing sugar and salt and beat until blended.
• Beat in the vanilla and cream and continue beating until light and fluffy.

For the marshmallow cream

• Beat the butter until soft and creamy. Sift in the icing sugar and beat until smooth.
• Beat in the marshmallow creme and vanilla until well blended.
• Turn half the cakes upside down and spread generously with the peanut buttercream.
• Spoon the marshmallow cream on top and place the remaining cakes on top.