Start first, I would suggest by preparing your baking sheet: Use parchment paper to line, definitely NOT foil. Making that mistake will cause horrible sticking and burning. Preheat your oven to 325.
In a large mixing bowl beat egg whites until soft peaks form (approx. 10 minutes by hand, 3-5 minutes by mixer).
If using Mixer, reduce speed and SLOWLY add the vanilla and then the powdered sugar. Gradually is the key here. Continue to mix for a minute or so longer or until all sugar is dissolved. If you are mixing by hand, add the vanilla and enlist the hands of a second person to help you pour the sugar in while you continuously whip the mixture. Ensure a smooth, light, glossy mixture.
Stop the mixer or put down your whisk and gently fold in your coconut about a cup at a time. Blend well.
Spoon the coconut mixture by approximate tablespoonfulls (rounded) onto the baking sheet and place immediately into the oven. Bake for 10-15 mins or until lightly browned on the tops. Garnish with cinnamon if desired.