Preheat the oven to 180°C / 350°F / gas 4. Prepare your lined tin.

Place the butter in a heatproof bowl along with the dark chocolate. Place a small amount of boiling water into a saucepan and rest the heatproof bowl with the butter and chocolate on top, then melt the contents on a low heat. You don't want the water to boil. Once melted set aside.

Add the sugar and eggs to an electric mixer and whisk for about 2 minutes until it's nice and frothy.

Pour the chocolate mixture into the egg mixture and whisk for a few minutes until everything is combined.

Sift the flour and and cocoa powder into the mixture and stir with a wooden spoon until you have a nice thick batter and everything is combined.

Pour all the mixture evenly into the prepared tin, gently bang the tin on the work surface to get rid of any air bubbles.

Bake in the oven for 25-30 minutes, make sure you check them with a metal skewer and the mixture is not too moist.

Let the brownies completely cool down it the tin, then transfer on to a wooden board.

While your brownies are cooling, make the peanut butter frosting. Using a whisk soften the butter for a few minutes, then add the peanut butter, icing sugar and whisk until it forms a paste. Add the milk to loosen the mixture — you may need more or less milk depending on the consistency of the peanut butter. Once the brownie has cooled, spread the peanut butter icing on top of the brownie.

To make the chocolate topping, melt the chocolate and butter using the same method in step 1. Take off the heat and leave to cool for at least 5 minutes. Carefully pour it all over the peanut butter layer. Sprinkle with peanuts. Leave to set in the fridge for 30 minutes.

Once set, cut the edges off so you have a nice, neat finish. Then cut up into 24 squares. Keep in the fridge and when ready to serve leave at room temperate for 20-30 minutes beforehand. Enjoy on their own or with vanilla ice cream.