1. Preheat the oven to 190˚C (Fan 160˚C, Gas Mark 5). 

2. In a large bowl cream the butter, sugar and lemon zest together. Into this mixture pour the beaten egg a little at a time, while adding a little flour to stop it curdling. Continue until all the egg and flour is mixed in together.
3.Next add the cranberries and milk and ensure all the ingredients are well mixed.

4. Grease and line a 26 x 16.5cm tin with parchment and spoon in the mixture. Level off the surface and bake for 30-35 minutes, or until firm to the touch in the middle.

5. Take out of the oven and while warm, sprinkle a generous amount of caster sugar onto the top and drizzle with the lemon juice. 

Leave to cool and cut into cubes for everyone to enjoy!