Note: Cornstarch is not strictly necessary for the success of this recipe, but it does help stabilize the filling if you plan to make the cheesecake ahead or serve it in a buffet setting.
For the brulee top crust:
4-5 tablespoons sugar
Special equipment: Culinary torch
For the burned sugar pieces (garnish):
1 cup sugar
2 teaspoons water
1 tablespoon corn syrup (if you have it, not strictly necessary)
Whipped cream (for garnish)
Special equipment: Parchment paper (not waxed paper)
To prepare crust and pan: Combine gingersnap crumbs, sugar and melted butter in a food processor; pulse to a fine crumb texture. Spray a 10-inch-round by 3-inch-deep cake pan or springform pan with cooking spray. Pat crust into the bottom and sides of pan, pressing with the bottom of a cup covered with plastic wrap to get the crust to stick.
If using a springform pan, cover the outside of the pan with at least two layers of heavy-duty foil, pressing tightly to seal. (This is to prevent the water bath from getting into the cheesecake. If you are using a regular cake pan, you do not need to wrap it in foil.) Set pan aside.
For the filling: In the bowl of a stand mixer fitted with the paddle attachment, combine cream cheese, sugar and cornstarch, if using. Beat at medium speed until smooth, scraping bowl often. Mix in the sour cream, scrape down bowl and mix again. Add eggs one at a time, beating after each addition. Mix in eggnog and nutmeg; scrape bowl and mix again. Stir in bourbon.
To fill crust and bake: Preheat oven to 290 degrees. Pour filling into prepared pan. Place cheesecake into a large roasting pan at least as deep as the cheesecake pan. (A disposable foil pan is fine, but place it on a cookie sheet for support.) Add warm water to the roasting pan until it reaches halfway up the sides of the cheesecake pan.
Place in oven and bake for 2 hours, 45 minutes, checking the water every 20-30 minutes or so, adding hot water as needed to keep the level halfway up the cheesecake pan. Turn off oven and leave cheesecake in there for another 30 minutes or so, to cool to room temperature with the oven, still adding hot water to the bath if needed.
When cheesecake cools to room temperature, refrigerate it at least overnight, up to two days.
To make burned sugar pieces for garnish: Cut a piece of parchment paper (not waxed paper) to fit a cookie sheet. Crumple the parchment into a tight ball, then smooth it out onto the cookie sheet. (The wrinkles will shape the brûlée pieces.) Combine 1 cup sugar and 2 teaspoons water in a small saucepan over medium heat. Cover pot, so the steam will wash any sugar granules down the sides of the pot, and cook about 5 minutes until sugar is a nice amber color.
Remove from heat and place pot in a larger bowl of cool water (not ice water) to stop the cooking, being careful not to get water in the pot. Pour the mixture over the prepared parchment, tipping and turning the pan as needed so the syrup forms a thin layer and doesn’t pool. Let cool for 1 hour at room temperature; do not refrigerate. When cool, break into pieces to use as garnish. (Can be made a few days ahead and stored in an airtight container at room temperature.)
For the brûlée top crust: Just before serving, unmold the cold cheesecake and carefully remove it from the pan. Sprinkle a thin layer of about 4-5 tablespoons sugar on top. With a culinary torch, brown the sugar to light amber, holding the torch 4-6 inches away from the cake and moving it constantly. If you still see sugar granules, go over that area again.
To serve: Garnish cheesecake with dollops of whipped cream and pieces of burned sugar garnish.
Nutrition information per serving: 621 calories, 37 g fat, 200 mg cholesterol, 10 g protein, 62 g carbohydrates, less than 1 g fiber, 414 mg sodium, 54 percent calories from fat.