Place into a bowl the butter and the caster sugar and use a hand mixer to mix until the fats are creamy and don’t have a gritty sugar texture.
Next crack into the bowl your eggs, add your vanilla and your lemon zest and mix slowly with the hand mixer.
Then add in slowly the flour and the milk along with the lemon juice from your medium lemons. Then mix well until you have a creamy lemon cake batter.
Pour the cake batter into two silicone baking pans and then place the silicone into the air fryer.
Air fry for 15 minutes at 180c/360f, then 10 minutes at 170c/340f followed by a final 10 minutes at 160c/320f. Or until a cocktail stick comes out clean. Then remove the lemon cakes from the air fryer and allow to cool, before peeling the silicone away from the cakes.
Place the lemon cake on a chopping board and slice into fingers. I recommend slicing in half and then into 5ths. This then becomes 10 and discard the two ends as this will make your cake a rectangle. Then make sure they are close together so that it doesn’t look like you sliced it as it will make it easier for serving.
Place the icing sugar and lemon juice from the two large lemons into a small bowl and mix with a spoon until you have a creamy, thick icing.
Use a spoon to spoon on the icing and then place in the fridge for 30 minutes to harden.
Next add a little yellow food colouring to the remaining icing in the bowl and mix well. Remove the cake from the fridge (after 30 mins) and using a spoon add a diagonal layer of yellow icing on top.
Then fridge for a final hour before serving.