Add the eggs one by one and mix briefly after each.
4 eggs
Add about half of the flour and mix briefly.
Pour in the buttermilk and mix until combined.
250 ml buttermilk
Add the rest of the flour and mix briefly.
Set aside about ⅓ of the batter into a smaller bowl.
Step 3 - preparing the chocolate batter
Add cocoa and milk to a smaller bowl - mix thoroughly. If the mixture is very thick, add a little more milk.
20 g bitter cocoa, 2-3 tablespoons milk
Step 4 - layering the batter
Spoon about ⅔ of the nut batter into the pan.
Spoon half of the chocolate batter on top of it in "dollops".
Spoon the rest of the nut batter, and on top of it, the rest of the chocolate batter.
Finally, swirl the batter with a skewer or knife.
Step 5 - baking the cake
Place the cake pan in the preheated oven and bake for about 35-40 minutes - until a dry stick comes out.
After baking, let the cake cool.
Step 6 - decorating the cake
Heat the heavy cream in a saucepan and when hot, add the broken chocolate to it.
100 ml heavy cream, 150 g chocolate
Stir until you get a smooth chocolate glaze. Let it cool and when it starts to thicken, spread it over the top of the cake.
Briefly heat the peanut butter in the microwave (30 seconds should be enough) and pour it over the chocolate glaze - immediately gently swirl the layers.
A glass has a capacity of 250 ml.See the notes below the recipe for possible substitutes for the ingredients used, or tips for the recipe. The recipe video is in Polish, but you can watch it to see the step-by-step process.