Mix the ingredients for the pancakes well and fry the pancakes in a pan with a little fat and set aside.
Preheat the oven to 170 ° C.
Peel the bananas, mash them with a fork and mix with 2 tablespoons of Nutella and the hazelnuts. Now distribute this on the pancakes, roll up the pancakes and cut into large pieces. Layer in a baking dish.
Mix the mascarpone together with the egg and powdered sugar well and pour over the pancakes. Bake the casserole for about 40 minutes.