To a saucepan, add all the ingredients for the cream sauce and warm over medium-low heat, stirring often, until the sauce comes together. It can be warmed back up when ready to use. Adjust the consistency with the heavy cream or more Nutella as desired.
Prepare the Waffles
Get your waffle iron heated up. In one bowl, combine the flour, baking powder, salt, sugar, and cinnamon. Mix well to combine. In another bowl whisk the egg and milk until thoroughly combined. Pour the milk and egg mixture into the dry ingredients and carefully whisk them until incorporated. Stir in the crushed cookies and the melted butter.
Lightly spray your waffle iron with cooking spray and add as much batter as is necessary for your waffle iron to make each waffle.
Serve with the Nutella Cream and, if desired, any of the additional garnishes.