Makes 12 servings at 75¢ each. Prep: 25 minutes. Bake: at 300° for 1 1/4 hours. Stand: in turned-off oven for 30 minutes; at room temperature for 1 hour.Refrigerate: 4 hours.
Heat oven to 300°F. Lightly butter sides and bottom of a 9-inch springform pan.
Combine 1/2 cup of toffee bits, gingersnap crumbs and butter in small bowl until well blended. Press mixture evenly over the bottom and 1-1/2 inches up side of prepared springform pan. Refrigerate while preparing batter.
Beat together cream cheese and sugar in large bowl just until smooth.
Beat in eggs, one at a time, on low speed, just until blended, scraping down side of bowl as needed. Add sour cream and vanilla; beat until smooth. Pour into prepared crust.
Fill 2-quart baking dish halfway with hot water. Place on lowest rack setting in oven. Position other rack in center of oven.
Bake cheesecake on center rack above water in 300°F oven for 1-1/4 hours. Turn oven off; leave cake in oven with door closed for another 30 minutes. Remove to wire rack and cool to room temperature, for about 1 hour. Cover with foil. Refrigerate for 4 hours or overnight. Remove side of pan. Cut into slices, wiping blade clean after each slice.
Warm caramel sauce in small saucepan. Stir in remaining 1/2 cup toffee bits. Spoon sauce over individual slices of cheesecake.