Preheat the oven to 350°F (175°C). Grease and line a baking pan with parchment paper.

In a mixing bowl, whisk together the sugar and melted butter until combined.

Add the eggs and vanilla extract, whisking until smooth.

Sift in the cocoa powder, flour, and salt. Stir until just combined.

Pour the brownie batter into the prepared baking pan and spread evenly.

In another bowl, beat the softened cream cheese and powdered sugar until smooth.

Add the egg and vanilla extract, mixing until well combined.

Fold in the chopped pistachios.

Pour the cream cheese mixture over the brownie batter and swirl gently with a knife.

Sprinkle additional chopped pistachios on top.

Bake in the preheated oven for 30-35 minutes, or until a toothpick comes out with a few moist crumbs.

Allow to cool in the pan before slicing into squares.