1Heat oven to 300°F. Spray 9-inch springform pan with cooking spray. In small bowl, mix crumbs and butter. Press in bottom of pan. Bake 15 minutes. Cool 10 minutes.
2In large bowl, beat cream cheese, 1/2 cup sugar and the vanilla with electric mixer on high speed until smooth. Beat in 2 of the eggs. Stir in 1 cup of the toffee bits. Spread over crust. In large bowl, mix pumpkin, whipping cream, 2/3 cup sugar, the cinnamon, salt and remaining 3 eggs just until blended. Slowly and carefully spoon over cheesecake layer.
3Bake 2 hours or until edge of cheesecake is set at least 2 inches from edge of pan but center still jiggles slightly when moved. Turn oven off; open oven door at least 4 inches. Leave cheesecake in oven 30 minutes. Run spatula around edge of pan. Cool 30 minutes. Refrigerate 6 hours or overnight. Run spatula around edge of pan; remove side of pan. Pipe whipped topping around edges of cheesecake; sprinkle with remaining toffee bits.