Pre-heat your oven to 160C Fan/180C/350F/Gas Mark 4, and line a muffin tin with cupcake cases
To make the sponge, mix together the butter and caster sugar using a electric mixer until smooth and fluffy
Add the eggs and prosecco extract, and whisk together until smooth
Whisk in the self raising flour gently until fully mixed in
Divide the mixture between the cupcake cases
Baked them for 20-25 minutes, or until golden and a thin skewer inserted into the centre comes out clean. Let them cool fully on a cooling rack
Use a cupcake corer or a knife to make a hole in the centre of each cake, then fill the holes with the strawberry jam
To make the buttercream, mix together the icing sugar, butter, milk and prosecco extract until smooth. Use an electric mixer for best results. You can add a little more milk if the buttercream is too stiff
Put into a piping bag fitted with your chosen nozzle and pipe it on top of each cupcake
Add the fresh strawberries and gold star sprinkles on top to decorate
Store leftovers in an airtight container in a cool place and eat within 3 days