Preheat oven to 355°F (180°C). Lightly butter the bottom and sides of a 9" round spring form pan with a piece of cold butter.

In a large bowl, combine crushed gingersnap cookies, melted butter, and salt. Mix together really well to combine. If your cookies aren't very sweet, you can add brown sugar. The gingersnap cookies that I used were very sweet so I didn't need to.

Add the crust mixture into the prepared baking pan. Spread it out to the edges and pack it in. Make sure to pack it up the sides as well.

Bake for 8-10 minutes, until lightly golden on the edges. While it bakes and cools, work on the cheesecake batter. Don't turn the oven off!

Add softened cream cheese into a large bowl or stand mixer. Beat with an electric mixer until creamy and smooth. Scrape down the sides so that it all incorporates smoothly and evenly. Add sugar, salt and vanilla, and mix, scraping down the sides.

Add eggs into the cream cheese one at a time, beating in between each egg to incorporate. Make sure to scrape down the bowl to ensure that it mixes evenly.

Pour the eggnog into the cheesecake batter. Add the grated nutmeg. Mix with a spatula until smooth.

Pour the cheesecake batter into the baked crust. Tap the pan on a flat surface to knock out any air pockets. Place the cheesecake pan into a slightly larger round pan or oven safe saucepan. Then place that in an even larger baking pan (see notes for water bath options).

Fill a kettle with water and set it to boil. Carefully transfer the pans and the cheesecake into the oven. Carefully pour the boiling hot water into the largest baking pan. Add water to about almost all the way up the middle pan. You may need a few kettles of water for this.

Bake for 70-80 minutes, until the edges are set, and the middle is puffed and jiggly. When ready, turn the oven off and don't take the cheesecake out yet. Leave the oven door propped open a bit to cool gradually for 20 minutes. Then carefully remove the cheesecake out of the oven, being careful of the hot water.

Let the cheesecake cool to room temperature then refrigerate for at least 8 hours or overnight.

For the cream to whip up easily, place the bowl and whisk in the freezer for about 5 minutes before starting.

Combine cream, sugar, and vanilla extract in the chilled mixing bowl. Whisk by hand or with an electric mixer until stiff peaks form.

Add the rum and gently fold until evenly incorporated.

Remove the cheesecake from its pan and top with the whipped cream. Sprinkle a bit of grated nutmeg on top. I also decorated it with sugared cranberries and rosemary along the border of the cheesecake. Enjoy!