Beat together the butter and sugar until light and fluffy!
Add in the egg, and vanilla, and beat again till smooth.
Adding the flour, bicarbonate, salt and cornflour and beat until a cookie dough is formed!
Add in the chocolate chips, mix, and press into the bottom of a 9x9" Square Baking Tin, lined with parchment paper.
Freeze for 20 minutes!
For the Brownie Layer
Preheat the oven to 180c/160C Fan.
Melt together your dark chocolate with your butter until smooth.
Whisk together the eggs and sugar into a thick mousse like mixture, and then fold through the melted chocolate mix.
Add in the flour, and cocoa powder, and fold through again.
Mix through the chocolate chips carefully and pour the batter onto the frozen cookie dough.
Bake the Brookies in the oven for 25-30 minutes, or until baked through. Sometimes it can take a smidge longer! There should be a slight wobble to the mix.
Leave to cool in your tin for 10 minutes, and then carefully remove and finish cooling on a wire rack. If you want, you can then chill the bake in the fridge for 3 hours or so to help create the fudgey texture.
Cut up into your portions and enjoy!
Notes
I think it's important to freeze the cookie dough, to help the brookies bake better. It is optional however! If you want, you can put the Cookie layer into the fridge for an hour instead of the freezer for 20 minutes!
The Cookie Layer is inspired by my Cookie bars, and the Brownie Layer is inspired by my Brownies!
These will last for 4-5 days easily, if not longer if they aren't already eaten!
You can use whatever flavour chocolate chip you want!