Cost per Serving:
Make crust: Preheat oven to 350°F. Spray bottom of a 10-inch springform pan with nonstick spray. Mix gingersnap crumbs, butter and brown sugar with hands until mixture holds together when pressed. Press into bottom of pan. Bake crust until firm and slightly darkened, about 12 minutes. Cool crust. Maintain oven temperature.
Make filling: Beat cream cheese and brown sugar in a large bowl until smooth. Beat in butter, then eggs, one at a time, to thoroughly incorporate. Mix in heavy cream. Add flour, cinnamon, vanilla extract and salt, and then mix until smooth. Add pumpkin puree and mix until smooth. Place springform pan with cooled crust on a large baking pan (crust will ooze some melted butter as cake bakes) and pour mixture into springform pan over crust.
Return to 350°F oven and bake for 1 hour and 10 minutes or until filling is puffed around edges and moves slightly in center when pan is gently shaken. Remove from oven and immediately place hot cheesecake, uncovered, in refrigerator; let cool overnight.
Make caramel topping: Combine sugar, water and lemon juice in a large saucepan over medium heat. After sugar dissolves, do not stir. Cook until mixture turns deep amber in color, occasionally swirling pan and brushing down sides with a wet pastry brush, about 15 minutes.
Reduce heat to low and add cream, stirring with a wooden spoon until bubbling subsides. Simmer, stirring occasionally, until reduced to 1 1/2 cups, about 8 minutes. Chill until firm but still pourable, about 15 minutes.
Remove cheesecake from refrigerator and spoon caramel over top, just to edges, being careful not to let it drip down sides. Make a ring from candy bar shards on edge of top of cake. Use white chocolate chips to make a jack-o'-lantern face in center. Chill for at least two hours and up to one day before serving. Gently run a knife around sides of pan to loosen the cake and release pan sides.