Place egg whites in a mixing bowl; let stand at room temperature for 30 minutes. Beat egg whites and cream of tartar on medium speed until soft peaks form. Gradually beat in gelatin. Add sugar, 1 tablespoon at a time, beating on high until stiff peaks form and sugar is dissolved.
Drop meringue into eight mounds on a parchment-lined baking sheet. Shape into 3-1/2-in. cups with the back of a spoon. Bake at 250° for 45 minutes. Turn oven off; leave meringues in the oven for 1 to 1-1/2 hours.
For filling, in a microwave or heavy saucepan, melt chocolate with water; stir until smooth. Cool. In a small mixing bowl, beat milk, vanilla and whipped topping mix until soft peaks form. Fold into melted chocolate. Spoon into meringue cups. Refrigerate until serving. Garnish with raspberries.