Set a rack in the middle and top third of the oven and preheat to 325 degrees F. In a completely clean, dry mixing bowl, with an electric mixer, whisk the egg whites, salt, and cream of tartar until very foamy and almost creamy. With the mixer still running, sprinkle in the sugar. Continue to whisk on high speed until fluffy, thick, and shiny. Whisk in the vanilla. Fold in the pecans, coconut, and corn flakes.
Drop walnut-size balls of batter onto nonstick or parchment-lined cookie sheets at 2-inch intervals. Bake for 15 minutes, turning the pans once, front to back, for even baking until lightly tanned and set on the surface. Set the cookie sheets on a rack to cool.