Unwrap the Creme Eggs and put them in the freezer.

Preheat oven to 180c/Gas Mark 4. Line a brownie pan with baking paper or parchment paper.

Cream butter and sugars in a large bowl. Mix in the vanilla extract and gradually add the egg – beating well. Stir in the milk.

Sift the dry ingredients – flour, cocoa powder and baking powder – into a large mixing bowl and then fold into the butter and egg mixture.

Transfer the cookie dough to the prepared brownie tin and smooth with a spatula. It’s fine if it doesn’t quite meet the edges.

Retrieve the Creme Eggs from the freezer and push down into the cookie dough.

Cover loosely with foil and bake for 15 mins. Uncover and bake for a further five minutes until lightly golden browned. It should still be slightly soft in the centre – like a giant cookie!