Caramel-Pecan Cheesecake Bars

1-1/2 cups NABISCO Graham Cracker Crumbs
1 cup coarsely chopped PLANTERS Pecans, divided
2 Tbsp. granulated sugar
1/4 cup (1/2 stick) butter, melted
4 pkg. (8 oz. each) PHILADELPHIA Cream Cheese, softened
1 cup firmly packed brown sugar
2 Tbsp. flour
1/2 cup BREAKSTONE'S or KNUDSEN Sour Cream
1 Tbsp. vanilla
3 eggs
1 bag (14 oz.) KRAFT Caramels, divided

Preheat oven to 350°F. Line 13x9-inch baking pan with foil, with ends of foil extending over sides of pan. Mix graham crumbs, 1/2 cup of the pecans, the granulated sugar and butter; press firmly onto bottom of prepared pan. Bake 10 minutes.

Beat cream cheese, brown sugar and flour in large bowl with electric mixer on medium speed until well blended. Add sour cream and vanilla; mix well. Add eggs, 1 at a time, mixing on low speed after each addition just until blended. Place 36 of the caramels and 1 Tbsp. water in microwavable bowl. Microwave on HIGH 1 minute or until caramels are completely melted when stirred. Add to cream cheese batter; stir until well blended. Pour over crust.

Bake 40 minutes or until center is almost set. Sprinkle cheesecake with remaining 1/2 cup pecans. Refrigerate at least 4 hours or overnight.