Preheat the oven to 325°F (163°C). Line the 9-inch springform pan with parchment paper on the bottom and grease the sides.
Combine the crust ingredients in a small bowl, then press the mixture into the bottom and up the sides of the springform pan.
Bake the crust for 10 minutes and let it cool.
Cover the pan's outer side with aluminum foil to prevent water from the water bath from seeping in. Refer to my tutorial for a leak-proof water bath. Set the prepared pan aside.
Reduce the oven temperature to 300°F (148°C).
In a large mixer bowl, blend cream cheese, brown sugar, and flour on low speed until completely smooth. Use low speed to avoid adding excess air to the batter, which can cause cracks. Scrape the bowl's sides.
Add mashed bananas, cinnamon, nutmeg, and dark rum. Beat on low speed until well combined.
Add eggs one at a time, beating slowly and scraping the sides of the bowl as needed.
Pour the cheesecake batter into the crust.
Place the springform pan inside a larger pan and fill the outer pan with warm water, going about halfway up the springform pan's sides. Ensure the water level stays below the top edge of the aluminum foil. Bake for 1 hour.
Turn off the oven and leave the cheesecake inside with the door closed for 30 minutes. Do not open the door to retain the heat.
Crack the oven door and leave the cheesecake inside for another 30 minutes. This gradual cooling prevents cracks.
Remove the cheesecake from the oven and let it sit on the counter for 15 minutes.
Remove the pan from the water bath and the aluminum foil. Refrigerate the cheesecake until completely firm, around 6-7 hours.
After the cheesecake has cooled, prepare the bananas foster. Melt butter in a large pan over medium-high heat.
Add brown sugar, nutmeg, cinnamon, and heavy cream. Stir until the sugar dissolves.
Pour rum into the pan and use a lighter to ignite it. Be cautious as the flame can be high. Let it burn for a minute or two, swirling the pan to disperse the rum and flames. It should extinguish itself; if not, swirl a little more.
Add the bananas to the sauce and cook for an additional 1-2 minutes to thicken. Remove from heat and set aside to cool and thicken before adding to the cheesecake.
While the bananas foster cools, remove the cheesecake from the springform pan and place it on a serving plate.
To make the whipped cream, combine heavy whipping cream, powdered sugar, and cinnamon in a mixing bowl. Whip until stiff peaks form.
Pipe a whipped cream border around the outside edge of the cheesecake.
To finish the cheesecake, add the bananas foster on top in the center of the whipped cream. Drizzle the sauce over the bananas and down the sides of the cheesecake.
Refrigerate the cheesecake until ready to serve. It's best enjoyed within 2-3 days due to the bananas on top.