Cut cone-shaped piece out of top of each cupcake; reserve for later use. Whisk 2 Tbsp. sugar and remaining sour cream in medium bowl until blended; stir in Cool Whip
. Spoon into resealable plastic bag. Cut corner off one bottom corner of bag; use to pipe Cool Whip
mixture into holes in tops of cupcakes. Top with reserved cake pieces, pressing gently into Cool Whip
mixture to secure.