Chocolate marble milkshake cupcakes recipe

Preheat the oven to gas 4, 180°C, fan 160°C. Line a muffin tin with 12 paper cases. In a bowl, beat the butter and sugar until light and fluffy. Add the vanilla, then beat in the eggs, one by one, each with a spoonful of flour, until smooth. Fold in the remaining flour and stir until just combined.
Put half the mixture into another bowl. Add the cocoa and milk chocolate to one bowl and milk to the other.
Fill each case with spoonfuls of both mixtures, then swirl with a knife or skewer to create a marble effect. Bake for 20-25 mins.
To make the buttercream, beat the butter in a bowl until pale and creamy, then add the vanilla. Add the icing sugar in 3 stages, beating between each addition, until fully combined. Divide between 2 bowls. Mix the melted dark chocolate into one bowl. Add both to a large bowl and swirl briefly with a knife to create a marble effect. Put into a piping bag with an open star nozzle.
Pipe the chocolate icing on top of the cupcakes, then sprinkle with chocolate curls. The iced cupcakes will last for 3 days in a sealed container.