Place parchment paper over a large baking sheet. Draw 8 (3-inch) circles on parchment paper. Turn parchment paper over, and secure with masking tape. Beat egg whites, vanilla, and cream of tartar at high speed of a mixer until foamy. Gradually add sugar, 1 tablespoon at a time, beating until stiff peaks form (do not underbeat). Fold 2 tablespoons cocoa into mixture.
Divide 1/2 cup egg white mixture evenly among the 8 drawn circles. Using the back of a spoon, shape egg white mixture into nests with 1-inch sides.
Bake at 225 for 1 1/2 hours or until dry. Turn oven off; let meringues cool in oven at least 12 hours. Carefully remove meringue nests from paper. Fill each meringue with Pastry Cream; top with fruit. Gently brush fruit with jelly.
Sprinkle 1/8 teaspoon cocoa over each serving, if desired.
