Pistachio and Raspberry Swirl Brownies

Ingredients

• 1 and 1/2 sticks of unsalted butter (190g), plus more for greasing the pan
• 2 cups of sugar (400g)
• 4 large eggs
• 1 teaspoon of pure vanilla extract
• 3/4 cup of unsweetened cocoa powder (75g)
• 1 and 1/4 cups of all-purpose flour (160g)
• 1 teaspoon of salt
• 1 cup of chopped fresh pistachios (120g)
• 1 cup of fresh raspberries
• 2 tablespoons of granulated sugar
• 1 tablespoon of cornstarch