Mix the dry ingredients (except for the dark chocolate). Add oil and water and mix everything well. Place on a baking tray lined with baking paper and distribute well. Put the peanut butter on top and fold in with a fork until it resembles a marble dough.
Bake in the oven at 180 ° C for 20-25 minutes. Take out and let cool for about 30 minutes.
Meanwhile, melt the chocolate and drizzle over it with a spoon. When the chocolate has cooled down, cut into squares.