• Preheat the oven to 180'C (170'C fan) / Gas 4. Fill either one 18-hole or two 12-hole muffin tins with fairy cake cases. This recipe makes around 18 fairy cakes so I tend to use two 12-hole tins.
• Add the butter, sugar and vanilla extract to a large mixing bowl and beat with an electric whisk until pale and creamy. (TIP: If the butter is hard, zap it in the microwave for 10-15 seconds before adding it to the mixing bowl to make it easier!)
• Crack the eggs into the mixing bowl and beat again for 30 seconds to combine. Scrape down the sides of the bowl using a spatula.
• Sift in the self-raising gluten free flour and xantham gum and then beat together with the electric whisk until everything is fully combined. Add the milk 1 tbsp at a time, mixing in between. You want a fairly thick batter which drops from the spoon easily, so you may need either 2 or 3 tbsp of milk.
• Spoon the mixture evenly between the cake cases and then place in the centre of an oven and bake for 20 minutes. The cupcakes are done when they are well-risen, golden on top, and a skewer inserted in the middle comes out clean.
• Once cooked, remove from the oven and place on a cooling rack. Cool in the tray for 10 minutes before removing the cakes from the tray to cool completely before icing.

To decorate the butterfly cakes

• Make the buttercream frosting by beating together the icing sugar, butter, milk and vanilla extract until pale and creamy.
• Use a sharp knife to cut a small circle out of the centre of each cake, about half the depth of the entire cake.
• Use a palette knife, teaspoon or piping nozzle to fill the hole with buttercream frosting. Cut the circle of cake you removed in half and place it on top, like butterfly wings.
• Sprinkle the cakes with icing sugar to finish before serving.