Heat the oven on gas mark 4, line a cupcake tin with cases. Beat the butter and caster sugar together until combined.
Add the eggs one at a time until fully incorporated. Then add your flour to the mixture and mix again until combined. Once all the ingredients are combined, add in the lemon extract and mix again.
Using a ice cream scoop, scoop the mixture into the cases and bake for 20 minutes. Once the cakes are cooked, leave them to cool on a wire rack.