Preheat oven to 325 degrees. Spray the sides of the 9.5-inch springform pan with nonstick baking spray. Wrap the sides of the pan with a strip of parchment paper.
In a mixing bowl, add the graham cracker crumbs, sugar, and melted butter. Stir until the butter coats all the crumbs.
Press the crumbs evenly into the bottom of the prepared pan.
Place in the oven and let bake for 15 minutes. Remove from the oven and let cool while you work on the cheesecake filling.
In a mixing bowl, add in the cream cheese and granulated sugar. Mix until completely incorporated. Scrape the sides and bottom of the bowl and mix again to avoid any lumps of cream cheese in your batter.
Add in the butter rum flavoring and eggs one at a time. Beat in each egg completely before adding the next. Scrape down the bowl after adding each egg.
Add in the sour cream and heavy cream. Mix until incorporated.
Just before adding the cheesecake mixture, wrap the outside of the springform pan with 2 layers of heavy-duty tin foil.
Pour the cheesecake filling on top of the crust.
Place the springform pan in a slightly larger baking pan. Fill the outer pan with 1 inch of water. This will keep the cheesecake from cracking.
Place in the oven at 325 degrees and let bake for 1 hour and 20 minutes or until done. To make sure the cheesecake is done, gently give it a wiggle. If it slightly jiggles in JUST the middle like jello, then it's done. If it jiggles all over, it needs to bake longer. Turn off the heat and crack the oven door slightly. Let it cool in the oven for 1 to 2 hours until it reaches room temperature and then place in the fridge to chill overnight.
Make the sauce and whipped cream after the cheesecake has chilled.
In a medium saucepan, add in the brown sugar and heavy cream. Place the pan over medium heat and stir frequently.
As soon as the sugar is dissolved, remove from the heat and stir in the butter and butter rum flavoring. It should only take about 1 to 2 minutes for the sugar to dissolve. I made my sauce crunchy by letting it stay on the heat for 3 minutes.
Pour the sauce on top of the cheesecake and spread out.
In a mixing bowl, add in the heavy cream. Beat until soft peaks form.
Add in the powdered sugar. Continue to beat until it becomes thick and stiff peaks form.
Add the whipped cream into a piping bag with a 1M tip. Pipe swirls on top of the cheesecake.
Refrigerate until ready to serve. Slice and serve.