Preheat oven to 325 F; grease and flour cookie sheets. In a large bowl, beat egg whites until frothy. Gradually add sugar and continue beating until stiff peaks form. Stir in almond extract. In another bowl, combine ground almonds, coconut and cocoa. Gently fold into egg whites. Drop small spoonfuls of batter onto cookie sheet, 1-inch apart. Bake 12 to 15 minutes until tops of macaroons are firm. Let cool on cookie sheet a few minutes, then gently remove to wire rack and let cool completely. Store in an airtight container.