Pre-heat your oven to 160C Fan/180C/350F/Gas Mark 4 and line a cupcake tin with cupcake cases
Make the cupcake sponge by mixing together the butter and the caster sugar until smooth and fluffy
Add the eggs and milk and whisk in well
Add the self raising flour, cocoa powder and baking powder and whisk in
Divide the mixture between the cupcakes cases, then place one Lindt Lindor truffle in the middle of each one
Bake them for 20-25 minutes. Put them on a cooling rack 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 melted chocolate and mix until smooth, then mix in the milk. if the buttercream is too stiff then you can add a little more milk
Pipe the buttercream onto each cupcake, or spread on with a spoon, then add another Lindt Lindor on top and sprinkles if using
Store in an airtight container in a cool place, eat leftovers within 3 days