1 tub (8 oz.) COOL WHIP Whipped Topping, thawed, divided
4 cups sliced fresh strawberries
1/3 cup sugar
Heat oven to 425°F.
Whisk sour cream, 1/2 cup milk and 3 Tbsp. sugar in large bowl until blended. Add baking mix; stir just until moistened. Spread onto bottom of 9-inch round pan sprayed with cooking spray. Bake 12 to 15 min. or until golden brown. Cool 10 min.; remove to wire rack. Cool completely.
Beat pudding mix and remaining milk in medium bowl with whisk 2 min. Stir in half the COOL WHIP. Toss strawberries with 1/3 cup sugar.
Cut cake horizontally in half; stack layers on plate, filling with half the strawberry mixture and all the pudding mixture. Top with remaining COOL WHIP, then strawberry mixture.