Preheat your oven to 325°F. Line two sheet pans with parchment paper & set aside.
In a stand mixer fitted with a whip attachment, begin to whip the egg whites on high speed until they reach soft peaks, or when you pull up the whisk attachment from the bowl & the meringue peaks barely hold their shape.
Switch the mixer to medium speed & gradually add the granulated sugar. Once incorporated increase the mixer speed to high & whip until stiff peaks form.
Switch the mixer to low, adding the the cinnamon followed by the hazelnuts.
Using two spoons, dip one into the mixing bowl to scoop up about a tablespoon of meringue. Use the other to place the meringue on the sheet pan. Repeat until all meringues have been scooped onto the trays.
Bake for 20 minutes, then turn down temperature to 250°F & bake for another 20 mintues or until meringues are featherlight.
Meringues will keep for a few weeks if stored in a sealed container.