Preheat oven to 325°F (165°C). In a large bowl, stir together the coconut, condensed milk, vanilla, and salt. Whisk the egg whites until frothy and fold them into the coconut mixture.

Drop heaping tablespoon-sized mounds onto a parchment-lined baking sheet, shaping each into a tall peak with damp fingers. Space them about 1 inch apart.

Bake for 20 to 22 minutes, until the edges and tips are deep golden brown. Cool on the baking sheet for 5 minutes, then transfer to a wire rack.

Once completely cool, drizzle with melted dark chocolate if desired. Let the chocolate set at room temperature before serving.