Heat oven to 350°F. Cover bottom of 9-inch springform pan with parchment paper. Combine chopped pecans, margarine and 2 Tbsp. sugar; press onto bottom of pan. Microwave caramels and milk in microwaveable bowl on MEDIUM 4 to 5 min. or until caramels are completely melted and mixture is well blended, stirring every 2 min. Spread over crust to within 1 inch of edge; cool.