For the muffins with chocolate and walnuts, prepare a muffin tray and place a baking paper cup in 6 wells. Place a baking rack in the center of the oven and preheat the oven to 180 °C top/bottom heat.
Prepare ingredients and weigh them. Combine flour, cocoa and baking powder and sift. Mix flour, cocoa, baking powder, salt, dark chocolate, sugar and walnuts in a mixing bowl.
Add vanilla pulp, milk, butter and egg. Mix briefly and well with an electric hand mixer or food processor. Divide the batter into individual muffin tins using 2 tablespoons (fill the tins only 2/3 full).
Bake the muffins with chocolate and walnuts for about 30 minutes. Test the muffins with chocolates and walnuts. Then let the muffins with chocolate and walnuts cool down a bit and transfer them to a wire rack.
Carefully remove the cooled muffins from the paper cups.