Preheat your oven to 180°C (356°F) and prepare a 15cm baking tray with baking paper and grease the sides.

Melt 100g of unsalted butter in a saucepan over low heat, stirring consistently. Add 1/4 cup of milk, 1 cup of sugar, and 1 teaspoon of vanilla extract, mixing until smooth, about 3-5 minutes.

Add 150g of chopped dark chocolate to the butter mixture and stir until melted and smooth, about 2-3 minutes. Remove from heat and let cool slightly.

In a separate bowl, sift together 1/2 cup of all-purpose flour, 1/3 cup of cocoa powder, and a pinch of salt.

Combine the warm chocolate mixture with the dry ingredients, mixing gently until just combined.

Pour the batter into your prepared tray and bake for about 20 minutes or until the top is crackly and a toothpick comes out with moist crumbs.

Let the brownies cool completely in the tray for about 30 minutes.

Melt 225g of dark chocolate in a saucepan over low heat, then stir in 1/4 cup of creamy peanut butter until smooth.

Spread the ganache evenly over the cooled brownies and refrigerate for at least 1 hour to set.

Once set, slice the brownies and serve.