Pre heat your oven to 180°C and line a 12 hole cupcake tray with cupcake cases.
To a large bowl add caster sugar and dairy free butter, beat until creamy. Add the eggs one at a time continuing to whisk between each addition. Add the vanilla extract and whisk again.
Add the gluten free self raising flour, baking powder and xanthan gum. Mix well until fully combined.
Divide the mixture between the 12 cupcake cases (to around 3/4 full) and level with a knife. Bake in the oven for around 20 minutes or until the cakes are golden brown and an inserted skewer comes out clean. Set aside to cool completely.