Preheat your oven to 350°F (175°C) and prepare an 8x8-inch baking dish by greasing it or lining it with parchment paper.

In a heatproof bowl, combine chocolate and butter and melt over simmering water, stirring until smooth.

In another bowl, whisk together eggs and sugar until pale and fluffy.

Combine the melted chocolate mixture with the egg-sugar mixture, folding gently.

Sift in flour, cocoa powder, and salt; fold in chopped pistachios.

Pour the batter into the prepared baking dish and spread evenly.

Bake for 25-30 minutes until a toothpick comes out with a few moist crumbs.

Let cool for 10-15 minutes in the pan before transferring to a wire rack.

Spread pistachio cream on top and sprinkle with crushed pistachios before slicing.