Preheat the oven to 165℃ (fan). Grease and line a 20x30cm baking tin.

Cut the butter into chunks, place in a heat proof bowl along with the dark chocolate.

Melt over a pan of simmering water until there are no lumps left, take off the heat and set aside to cool slightly.

Use an electric whisk to beat the eggs, egg yolk and the sugar until it is pale and thick, it should double in size.

Pour the melted chocolate and butter into the egg/sugar mix and fold through, be careful not to knock the air out of it. Use the figure of 8 method, going around and under.

Use a sieve and add the flour and cocoa through the sieve.

Fold the mix all together, then fold through the chocolate chips.

Pour the fudgy mixture into your lined baking tray. This recipe works best with a 20x30cm baking tin. Spread the mix into the corners.

Dollop the pistachio crème over the top of the mixture, then use a fork to swirl it all over.

Bake for 22-25 minutes. It should have a slight wobble in the middle and will have formed a paper like crust.

Leave it to cool until it is at room temperature. I like to put it in the fridge for a few hours before cutting it into portions. Enjoy!