Preheat the oven to 180'C / Gas 6. Fill a 12-hole cupcake tray with 12 cake cases and set aside.

Add the butter and sugar to a large mixing bowl and beat with an electric whisk until pale and creamy. Add the eggs and vanilla extract and beat again - don't worry if it curdles, the flour will fix this!

Sift in the flour and xanthan gum and mix again until fully combined. Add the prosecco and beat for another 30 seconds to mix in. Spoon the mixture evenly between the cake cases and bake in the middle of a hot oven for 20-25 minutes. You want them to be golden and spring back when touched lightly.

Remove the cakes from the oven and leave in the tin to cool for 5 minutes, before removing onto a baking rack to cool completely. Meanwhile, make the frosting.

Add the room-temperature butter to a large mixing bowl and beat for 3-4 minutes until it becomes pale. Add the icing sugar and prosecco and continue to beat on slow-to-medium speed until smooth. Spoon into a piping bag fitted with a large star nozzle (tip, if the mixture is very soft then put in the fridge for 15-20 minutes until firm enough to pipe).

Pipe the frosting onto the cupcakes in swirls, and then top with the sprinkles and edible glitter. Leave to firm for 10-15 minutes before eating.