Preheat oven to 350°. Coat 18 muffin cups with cooking spray., Beat first 4 ingredients until well blended. In another bowl, whisk together flour, sugar, cocoa and baking soda; gradually beat into egg mixture alternately with buttermilk., For filling, beat ricotta cheese, sugar and egg white until blended. Stir in coconut and extract., Fill prepared cups with half of the batter. Drop filling by tablespoonfuls into center of each cupcake; cover with remaining batter., Bake until a toothpick inserted in cupcake portion comes out clean, 28-33 minutes. Cool 10 minutes before removing from pans to wire racks; cool completely. Dust with confectioners' sugar.