1: Beat the egg whites with a pinch of salt until stiff peaks form.
2: Add sweetener, vanilla, and cinnamon to the egg whites and reserve.
3: Beat the egg yolks with the Nutella fit and add to the egg white mixture.
4: While mixing, add oats and mashed bananas.
5: Grease the cupcake mold with oil and sprinkle cinnamon.
6: Place apple slices covering the bottom of the mold and add chopped walnuts.
7: Pour the batter into the mold and bake in the oven at 200° C for approximately 15 minutes.
