Pre-heat the over to 180 degrees/Fan 160 degrees/Gas 4. Put muffin cases into a 12-hole muffin tin.
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, baking powder and lemon zest in to the bowl and then mix until fully incorporated then add the milk until mixed in.
Fill each cupcake case until about ¾ full then place in the oven to cook for 20 - 25minutes.
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.