Preheat oven to 350°F. Bring a kettle of water to boil for the water bath.
Tightly wrap (1) 9-inch springform pan in heavy duty foil. This step helps to prevent leaks when using a water bath. However, my favorite way to prevent leaks is to place a 9-inch springform pan into a 10-inch round cake pan. Both pans will go into a large roasting pan when baking the cheesecake. You will get all of the benefits of baking with a water bath without the risk of leaks.
In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl with an electric mixer, beat cream cheese and sugar for about 2 minutes. Scrape down the sides of the bowl and mix for an additional 30 seconds. Add in eggs, one at a time, scraping down the sides of the bowl after adding the second and fourth egg. After adding the final egg and scraping the sides of the bowl, mix again for 30 seconds. The mixture should be smooth and creamy. Add in the vanilla and heavy cream and mix for an additional 30 seconds.
4 (8-ounce) packages cream cheese, 1 cup granulated sugar, 4 large eggs, 2 teaspoons pure vanilla extract, 1/3 cup heavy cream
Place mini marshmallows into a large microwave-safe dish. Microwave in 15 second intervals until marshmallows are puffed and melty. Stir until smooth. Add melted marshmallows to the cream cheese filling and mix until just combined.
1 cup mini marshmallows
Pour the cheesecake filling over the prepared crust.
1 prepared graham cracker crust
Place the 9-inch springform pan into a 10-inch cake pan and place both pans into a large roasting pan. Pour boiling water into the roasting pan until it is halfway up the side of the cake pan. Gently lay a piece of foil over the pan – do not tighten the foil as we want to allow the air to still circulate.
Bake 55-65 minutes, the edges will appear to be set, but the center will still have some jiggle to it. At this point, turn off the oven, and leave the oven door cracked. Allow the cheesecake to rest in the cooling oven for one hour.
After one hour has passed, carefully remove the cheesecake from the water bath and place on a cooling rack to cool completely. Once the cake is completely cooled, place it into the refrigerator for at least 8 hours.
Just before serving, top the cheesecake with hot fudge sauce and toasted marshmallows.
hot fudge sauce, 12-15 regular marshmallows
Notes
Storage
Store covered in the refrigerator for up to 3 days or freeze for up to 1 month. For additional freezing details and instructions, including how to freeze the cheesecake whole to serve later, see the "Make Ahead and Storage" section in the post.