Preheat oven to 350 degrees F. Spray doughnut pan with non stick cooking spray and set aside.
In small bowl, combine Nutella, egg, egg yolk and flour until smooth batter forms. Spoon evenly into pans and spread batter around to fill cavities evenly.
Bake 8-10 minutes or until thoroughly cooked. Remove from oven and cool 10 minutes before removing from pans. Cool completely. Spread more Nutella over tops of doughnuts and garnish with chopped hazelnuts, if desired. Serve.
by The Savvy Kitchen