Pre-heat the over to 180 degrees/Fan 160 degrees/Gas 4. Line a baking tray with greaseproof paper.
Measure your butter and sugar into the bowl and cream together until fully incorporated. Add each egg and mix until both are combined.
Sieve your flour and baking powder in to the bowl and then mix until fully incorporated then add the vanilla extract and milk until mixed in.
Add the food colouring and stir in until you have your desired colour. Pour the mixture into the tin then place in the oven to cook for 20 minutes.
Once cooked, remove from the oven and leave to cool in the tin for a minute on a cooling rack then remove from the tin and place on cooling rack until fully cooled.