For the cupcakes
For the vanilla syrup
For the buttercream
Heat oven to 180C/160C fan/gas 4 and line a 12-hole cupcake tin with paper muffin cases. Put all of the cake ingredients into a bowl and whisk with electric beaters for 3-4 mins until light and pale. Divide the mixture evenly between the cases and bake for 20 mins or until a cocktail stick inserted into the centre of one of the cakes comes out clean. Leave to cool on a wire rack.
Mix together the maple syrup, vanilla extract and 1 tbsp water. Use a cocktail stick to poke a few tiny holes in each of the cooled cupcakes then drizzle a little bit of the syrup over each one.
Beat together the butter, icing sugar, milk and vanilla until smooth and pale. Put half the buttercream in one bowl and leave as it is, then divide the other half into 3 bowls. Use the food colouring to dye one pink, one pale green and one pale blue, then transfer them all to one large piping bag fitted with a large star nozzle, including the plain. Pipe swirls on top of the cupcakes – as the buttercream comes through the bag, the colours will start to blend and change as you pipe. Decorate the tops of the cupcakes with your favourite sprinkles if you like.