Heat oven to 300 degrees.
Spray a 9 or 10″ springform pan with cooking spray.
In a small bowl, mix crumbs and butter.
Press in bottom of pan. Bake 15 minutes. Remove from oven and set aside.
In large bowl, beat cream cheese, ½ cup sugar, and vanilla until smooth.
Beat in 2 of the eggs.
Stir in 1 cup of the toffee bits.
Spread over crust.
Mix pumpkin, whipping cream, ⅔ cup sugar, the cinnamon, pumpkin pie seasoning, salt and remaining 3 eggs just until blended.
Slowly and carefully spoon over cheesecake layer.
Bake for 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 or whipped cream around edges of cheesecake; sprinkle with remaining toffee bits.