Put chocolate, peanut butter and regular butter in a pot and melt it on low heat. Stir and make sure it doesn’t start to boil.
When it is melted, add in sugar and check that the mixture is not too hot (wait and cool it down if it is), because now you need to whisk in eggs, one by one. Put flour, salt and cocoa powder in a bowl and stir then add it to the chocolate mixture while whisking.
Pour the batter in baking tray with baking paper. I used baking tray size 36x21,5 cm.Now you can drip and swirl peanut butter with a spoon on top. Just heat it up a bit before so it will be liquid and run smooth. Sprinkle peanuts on top.
Bake it in preheated oven on 180 degrees Celsius for 35 minutes. Take it out of the oven and leave to cool down, then slice and serve.