Brownie mix:
Filling:
Preheat the oven to gas 4, 180°C, fan 160°C. Grease a 20cm baking tin and line with nonstick baking paper.
Put the butter on to melt in a small saucepan. (Take a tsp of this and add it to another pan to toast the filo in). Add 150g chocolate. Give the mixture a good stir, then continue to heat until melted together. Remove and set aside to cool a little.
Tear the filo pastry into small pieces and toast in the butter until golden and crunchy. Set aside in a bowl.
Take the pistachio cream and warm in the microwave for a few seconds, stir until smooth (set aside a tbsp for topping). Add into the filo pastry and mix thoroughly. Set aside.
Put the sugar, eggs and vanilla (if using) in a separate bowl and briefly whisk to combine. Stir in the cooled chocolate mixture. Sift in the flour and cocoa, then you can add the remaining chocolate and mix well.
Pour half the mixture into the prepared tin, then add layer of pistachio mixture, top with the rest of the brownie mixture. Drizzle the rest of the pistachio cream over the top. Bake for 20-25 mins, until a thin crust forms on the surface with a slight wobble.
Remove from the oven and leave to cool in the tin for 30 mins, before transferring to a wire rack to cool completely. Cut into 36 squares and chill until ready to serve. Enjoy cold from the fridge, at room temperature of warmed in the microwave for 10 secs. To freeze the brownies, wrap tightly in foil and eat within 2 month. Defrost for 1 hr at room temperature.
