TOSS together graham crumbs, margarine or butter and 2 tablespoons sugar in a small bowl. Reserve 2 tablespoons of crumb mixture for garnish. Press remaining crumb mixture onto bottom and 2 1/4-inches up sides of 9-inch springform pan. Chill in freezer while preparing filling.
BEAT cream cheese on medium speed of electric mixer in a medium bowl until fluffy. Add 1 1/3 cups sugar, cornstarch and vanilla. Beat until combined. Add eggs, one at a time, beating until just combined after each addition. Stir in sour cream.
POUR into crust. Bake at 325°F about 1 1/4 hours or until center is almost set. Cool on wire rack for 15 minutes. Loosen sides of pan. Continue cooling on wire rack for 45 minutes more.
SPRINKLE top with reserved crumbs. Refrigerate at least 3 hours. Garnish as desired. Store in refrigerator.