01 -
Blend butter, sugar, and brown sugar together until fluffy and creamy. Add in the egg and vanilla, mixing again. Carefully fold in the flour, baking soda, baking powder, and salt just until everything sticks together. Throw in the chocolate chips at the end and put the dough in the fridge to chill while you move on to brownies.
02 -
Switch on the oven to 340°F (170°C) and line an 8x8 inch (20x20cm) pan with parchment. Slowly melt chocolate and butter, then stir till smooth and glossy. In another bowl, whip eggs, both sugars, and vanilla for 3 minutes till airy. Mix the melted chocolate in. Gently fold in flour, cocoa, and salt using a sieve for smoother batter.
03 -
Pour half the brownie mix into the pan, spreading it nice and flat. Add dollops of Nutella and pistachio spread over it generously. Carefully top it all off with the remaining brownie batter, spreading it to hide the filling inside.
04 -
Take chunks of the cold cookie dough and drop spoonfuls all across the brownie layer to cover most of the surface.
05 -
Pop it into the oven for 28 minutes if you want a soft and gooey center. For a firmer bite, leave it in for 30-35 minutes. The cookie top should be golden with the edges starting to pull away from the pan.
06 -
Let everything cool completely before slicing it into neat squares. If you’re after picture-perfect edges, chill it in the fridge for an hour first.