First up let’s make the cookie dough, preheat your oven to 180°C/160°C fan/Gas Mark 4. Grease and line a 9” square baking tin. Pop your butter and sugar into a large bowl and whisk together until smooth and pale in colour.
Pop in the egg yolk and Vanilla Extract and whisk again until smooth. Sieve over the flour and Baking Powder and mix until the dough comes together. Finally pour in the crushed mini eggs and mix into the cookie dough.
Roll your cookie dough into small balls of dough, then pop onto a board lined with greaseproof and refrigerate.
Now it’s time to make the brownie, melt the chocolate and butter in the microwave in 30 second bursts, stirring between each burst until the mixture is melted. Add the sugar and beat until smooth and combined.
Pop in the eggs and Vanilla Extract, then whisk on a high speed for 2-3 minutes, this is easiest to do with a freestanding or electric hand whisk. It is whisking in the eggs really well that gives the brownie a lovely paper top.
Sieve the flour and Cocoa Powder on top of the mixture and fold through until just combined. Pour a thin layer of brownie into the base of your prepared tin. Pop in the balls of cookie dough so they are randomly scattered in the tin. Pour your remaining brownie mix over the top of the cookie dough and smooth the top.
Pop in the oven and bake for 35-40 minutes until the edges of your brownie have set but the centre still has a slight wobble. Leave to cool the in the tin.
Once your brownie has cooled, melt the chocolate separately in the microwave in 20 second bursts stirring between each burst. Use a spoon the drizzle the melted chocolate over the top of your brownie.
Finally sprinkle over some mini eggs, we like to keep some whole and crush some. Leave your chocolate to set and then slice your brownie and you are ready to serve!