1.Preheat oven to 350 degrees. Thoroughly combine coconut, granulated sugar, egg whites, vanilla, and salt in a large bowl using your hands or a wooden spoon. Form 2 tablespoons of the mixture at a time into 2-inch-tall trees with your hands, using your fingertips to make pointed tops. Transfer each tree to a parchment-lined baking sheet, spacing them 1 inch apart.
2.Bake until edges are golden and trees are firm, 12 to 14 minutes. Let cool on baking sheet on a wire rack at least 15 minutes. Cookies can be made up to 1 day ahead; dust with confectioners' sugar just before serving.