In a small bowl, mix the sugar, cinnamon, salt, and cayenne pepper together with a fork until it is evenly mixed.
In a large mixing bowl, whisk the egg whites until very frothy. Whisk in the maple syrup until it is evenly mixed. Toss in the pecans until they are completely coated with the egg/maple syrup mixture. Sprinkle the cinnamon sugar over the top and toss again to coat evenly. Spread the nuts in a single layer on the silpat or sprayed parchment lined sheet.