Pre-heat the oven to 180°C / 350°F / Gas Mark 4. Line a cupcake tin with 12 cupcake cases

Mix the butter until softened, then add the caster sugar. Beat on high speed until the mixture is pale and fluffy

Mix the eggs and vanilla extract together. Add to the butter/sugar mixture a third at a time, ensuring each addition is well incorporated before adding the next

Sift the flour and cocoa together. With the mixer on a slow-medium speed, add the flour 1 spoonful at a time. Stop mixing when all the flour has been incorporated

You should have a smooth soft, but not runny, batter. If needed, add cream or milk to loosen the batter.

Spoon a heaped teaspoon of batter in the bottom of each case, then place a half teaspoon of the white chocolate spread in the centre

Divide the remaining batter between the cupcakes so that each case is about ¾ full, then bake for 20 minutes or until the top is firm and springy. Place on a rack to fully cool

While the cupcakes cool, make the buttercream. Add the butter to a clean mixer bowl and beat until softened

Add in the icing sugar and mix well, then add in the chocolate hazelnut spread. Scrape down the sides if necessary, then beat the buttercream on the highest speed until you have a smooth mixture that forms soft peaks. If necessary, add a little cream a tablespoon at a time

Put the buttercream in a piping bag with a large star tip. If the cupcakes have cooled, pipe a swirl on the top of each cupcake

Decorate the top with a few chocolate vermicelli sprinkles and a single square of a kinder bueno