Line two cookie sheets with parchment paper or silicone baking sheets. Combine the egg whites, flaked coconut, sugar, vanilla and salt in a large heatproof mixing bowl, preferably stainless steel because the mixture will heat faster than in glass. Set the bowl directly into a wide skillet with a small amount of barely simmering water. If your bowl bobs in the water, simply pour some out. Stir the mixture with a silicone spatula, scraping the bottom to prevent burning. Stir until the mixture is very hot to the touch and the egg whites have thickened slightly and turned from translucent to opaque, about 5 to 7 minutes.
Set the batter aside for 30 minutes to let the coconut absorb more of the flavor. Preheat the oven to 350 degrees F. Position the oven racks in the upper and lower thirds of the oven. Using 2 tablespoons of batter, make heaps 2 inches apart on the lined cookie sheets. Bake for about 5-7 minutes or just until the coconut tips begin to color. Then rotate the pans from top to bottom and from front to back, to ensure even baking.
Lower the temperature to 325 degrees F and bake for another 10 to 12 minutes, until the cookies are golden with deep brown edges. Set the cookie sheets on racks to cool. Let the cookies cool completely before gently peeling the parchment away from each cookie. The cookies are best served on the day they are baked. The cookies can be stored in an airtight container for 4 to 5 days.
Optional- Chocolate Drizzle: While the cookies are still hot, top each with a little piece of your favorite milk or dark chocolate and let it melt. Or drizzle a little melted chocolate over each cookie.