Pre-heat your oven to 160C Fan/180C/350F/Gas Mark 4, and line a cupcake tin with cupcake cases

To make the sponge, mix together the butter and sugar, using a silicone or wooden spoon, until smooth

Then add the eggs and peanut butter and whisk them in

Then gently whisk in the self raising flour

Divide the mixture between the cupcakes cases. Place two of the frozen Mini Reese's Peanut Butter Cups on top of the batter of each cupcake

Bake them for 20 minutes or until a skewer inserted in the cupcakes comes out clean. Leave to cool completely

To make the buttercream, mix together the butter and icing sugar with a spoon or electric hand whisk, when it starts to come together, add the Reese's Spread and mix it in until smooth. If the buttercream is too stiff, add a splash of milk

Put the buttercream in a piping bag with a star nozzle and pipe it onto the cupcakes, or spread on with a spoon

To decorate, cut two Reese's Mini Peanut Butter Cups in half and place them on top of the buttercream

Store in an airtight container in a cool place, eat leftovers within 3 days