Preheat the oven to 180C (160C Fan) and line an 8" square baking tin with baking paper.
Put the chocolate and butter into a large bowl and melt in the microwave on 20-second bursts stirring in between each burst until completely melted and smooth. Leave to one side.
In a separate bowl whisk the eggs and sugar together until they have doubled in volume.
Pour the chocolate mixture into the egg mixture and fold them together. You need to be gentle during the stage because you don’t want to knock all the air out of your eggs.
Add in the flour and fold again until they are all completely incorporated
Fold through the salted peanuts until they are evenly distributed.
Pour half of the brownie mixture into your baking tin. Add half the salted caramel drizzling over the brownie mixture.
Pour the remaining half of the brownie mixture into the tin and drizzle over the remaining caramel.
Using a cake skewer swirl the caramel through the brownie mixture.
Bake in the oven for 30-35 minutes. You will know they are ready because they will have a slight wobble
Leave to cool in the tin for 15-20 minutes before moving to a wire rack to cool completely.