In a large mixing bowl allow egg whites to stand at room temperature for 30 minutes. Meanwhile, cover a large baking sheet with parchment paper or foil. Draw six 3-inch circles, 3 inches apart, on paper or foil; set aside.

For meringues, in a small bowl stir together the 2/3 cup sugar and the orange peel. Set aside. Add cream of tartar to egg whites. Beat with an electric mixer on medium speed until soft peaks form (tips curl). Add the sugar-orange peel mixture, 1 tablespoon at a time, beating on high speed until stiff peaks form (tips stand straight). Spoon egg white mixture into the circles on the prepared baking sheet, building up sides slightly.

Bake in a 300 degree F oven for 35 minutes. Turn off oven. Let meringues dry in oven with door closed for 1 hour. Remove from oven; cool completely on baking sheet.

For filling, stir together the 4 teaspoons sugar and the cocoa powder. In a small bowl stir together mascarpone cheese and vanilla. Stir in the cocoa mixture and enough of the milk to make of spreading consistency. Spread cocoa mixture in cooled meringues. Top with raspberries. If desired, garnish with mint. Makes 6 servings.

Prepare as above through step 3. Transfer to an airtight storage container. Store at room temperature up to 1 week. To serve, prepare filling and serve as above.