Meanwhile, beat cream cheese and butter in large bowl with mixer until well blended. Gradually beat in sugar. Whisk in Cool Whip
. Spoon 1-1/2 cups into small freezer-weight resealable plastic bag; seal bag. Cut small corner off bottom of bag. Poke hole in top of each cupcake with handle of wooden spoon. Insert tip of bag into hole in cupcake to pipe about 1 Tbsp. frosting into centre of cupcake.