Cover bottoms of 2 (9-inch) round pans with parchment paper; spray with cooking spray.
Add enough water to lime juice to measure 1-1/3 cups.
Add to cake mix in large bowl with eggs and oil; beat with mixer on low speed just until moistened. Scrape bottom and side of bowl; beat on medium speed 2 min.
Pour into prepared pans.
Bake 25 to 30 min. or until toothpick inserted in centers comes out clean. Cool 10 min.; remove to wire racks. Cool completely.
Mix sour cream and sugar in large bowl with whisk until well blended. Stir in COOL WHIP and lime zest; spoon 3/4 cup into medium bowl.
Add chopped pineapple and mint; mix well.
Stack cake layers on plate, filling with pineapple mixture. Frost with remaining COOL WHIP mixture.