This is a recipe for moist and rich chocolate muffins using plenty of Nutella and chocolate. Mix granulated sugar, eggs, milk, and melted butter, then add sifted cake flour, cocoa powder, and baking powder and mix well. Mix chopped dark chocolate into the batter, pour into muffin tins, add Nutella to the center, top with more chocolate, and bake. This is an easy recipe that even beginners can make, perfect for a snack or as a gift.