CRUST: Heat oven to 350 degrees F. In a small mixing bowl, combine crust ingredients. Pat into the bottom of springform pan and bake for 10 minutes.
CHEESECAKE: Directions for Filling: In the bowl of a mixer, beat cream cheese, sugar, flour and vanilla extract until just combined. Add egg yolks and egg, beat on low until just combined. Add milk and Nutella and mix completely. Pour filling into springform pan. Reduce oven temperature to 300 degrees F. Place springform pan on a cookie sheet and then place in oven. Bake for 1 1/2 hours, or until center appears set when shaken lightly. Remove and cool on a wire rack.
TOPPING: Bring cream to a boil. Pour over chocolate chips. Stir until smooth. Spread evenly over top of cheesecake. Sprinkle toasted hazelnuts over chocolate. Refrigerate cheesecake for at least 4 hours to set.