Heat oven to 350°F.
Mix coconut, cornstarch, sugar, egg whites and vanilla in heat-proof bowl.
Set bowl over a pot of boiling water (or use a double boiler). Heat, stirring until the mixture thickens, about 4 minutes. Remove from heat and set aside.
Spoon out macaroons, about a scant tablespoonful each, and place on ungreased baking sheet.
Bake at 350° for 10-15 minutes or until lightly golden but still soft and chewy. Remove to a wire rack to cool.
Place chocolate in a small microwave-safe bowl and heat on HIGH power for 1 minute. Stir until smooth, microwaving more if needed. Dip bottoms of cookies in chocolate, allowing excess to drip back into bowl. Place on a waxed-paper-lined baking sheet in refrigerator to set.
30 servings
* The % Daily Value (DV) tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.