Melt the butter and add this to a bowl with the sugars. Combine until smooth.
2. Whisk in the egg until well combined.
3. Sift in the flour and stir until a dough forms.
4. In a sandwich bag, crush the mini eggs and add to the dough.
5. Scoop out even balls and press slightly onto a lined baking sheet, spacing them out. I made 10 medium cookies.
6. Bake at 170C for 10-12 mins until golden and leave to cool slightly - they will continue cooking slightly, before diving in.