Place the large Crème eggs into the freezer. Preheat the oven to 180C/160C fan/gas 4. Line a 12-hole muffin tin with cupcake liners.
Beat the sugar and butter or margarine together in a bowl until light and fluffy. Slowly add in the eggs and a tablespoon of flour at a time. Sift in the rest of the flour and the cocoa powder and mix well. Stir in the milk and mix again.
Put one spoonful of the cupcake mixture into each paper case. Take the Crème eggs out of the freezer and place one whole egg into the case, pressing it down gently into the mixture. Put another spoonful of the cupcake mixture on top of each egg. Using the back of a teaspoon, gently even out the cupcake mixture in the case, so that the top of the Crème egg is just showing.
Bake in the oven for 15 minutes. Take the cupcakes out of the oven, let them cool in the tin slightly and then place them onto a wire rack.
To make the vanilla frosting, beat the butter for a few minutes until it is pale and creamy. Slowly add in the icing sugar until it is all incorporated and beat for a few minutes. Add the vanilla, followed by the milk to loosen the mixture slightly. Transfer the buttercream into a piping bag fitted with a round-holed nozzle.
Pipe the buttercream onto each cupcake and decorate each cake with one mini egg, cut into two halves.
Recipe by Ren Behan - Author Wild Honey and Rye at https://www.renbehan.com/2020/04/recipe-creme-egg-cupcakes.html