Prepare the crust: Preheat oven to 325°F (163°C). Mix graham cracker crumbs, sugar, cinnamon, and melted butter. Press into a 9-inch springform pan. Bake for 8 minutes, then cool.
Make the cinnamon swirl: Combine brown sugar, melted butter, cinnamon, and flour into a thick paste. Set aside.
Create the filling: Beat cream cheese and sugar until smooth. Add sour cream, vanilla, and heavy cream, mixing well. Add eggs one at a time, mixing on low until just blended.
Assemble: Pour half the filling over the crust. Dollop half the cinnamon swirl and swirl with a knife. Add remaining filling, then repeat with remaining cinnamon swirl.
Bake: Place pan in a water bath. Bake for 55–65 minutes until edges are set and center jiggles slightly. Turn off oven, crack door, and cool inside for 1 hour.
Chill: Refrigerate for at least 4 hours or overnight.
Make frosting: Beat cream cheese, powdered sugar, milk, vanilla, and cinnamon until smooth. Spread or pipe over chilled cheesecake.
Serve: Slice and enjoy!