Start by pre-heating your oven to 180c. Also grease and line an 8 inch square cake tin.
In a pot, add the butter and dark chocolate. Place this onto medium heat and heat until melted. You can also just do this in your microwave. Leave this aside to cool down.
In a large bowl, add the eggs, granulated sugar and brown sugar. Whip these together until your mixture lightens in colour and increases in volume slightly. This will take about 2 minutes.
Pour the cooled melted butter and chocolate mixture into this, whisk this in.
Add the flour, cocoa powder and salt, whisk just until combined.
Pour this into your prepared cake tin.
Melt your pistachio cream in your microwave slightly, then drizzle this over your brownie batter. Use a knife or skewer to swirl this around.
Now sprinkle your chopped pistachios and chocolate chips over this.
Place this into your pre-heated oven and bake for around 50 minutes to 1 hour, or until a toothpick inserted into the centre comes out with a few moist crumbs on it.
Once baked, I sprinkled some flaky salt over the brownie, this is optional.
Leave to cool at room temperature for about 20 minutes, then leave in your fridge to cool and set up for about an hour.
Now you can cut the brownie into pieces and enjoy!
