Preheat oven to 325°F (163°C) and grease a 9-inch springform pan. Wrap the pan with heavy-duty aluminum foil to protect from water leaks during baking.
In a bowl, combine graham cracker crumbs, brown sugar, cinnamon, melted butter, and vanilla. Press evenly onto the bottom and halfway up the sides of the pan to form the crust.
Mix brown sugar, cinnamon, and flour in a medium bowl. Stir in melted butter until consistent. Pinch small bits to layer later in the cheesecake.
Beat cream cheese and sugar on medium-high until smooth. Add vanilla and sour cream, mixing well. Add eggs one at a time, beating after each. Add cornstarch and then heavy cream gradually. Mix until smooth.
Spread one-third of cheesecake batter over crust. Sprinkle some cinnamon filling bits evenly, then add another third of batter. Repeat layering with cinnamon filling and finish with remaining batter and topping.
Place springform pan in roasting pan and pour hot water halfway up the pan’s sides. Bake for 70-75 minutes until edges are set and center slightly jiggles.
Turn off oven, leave door ajar, and let cheesecake rest inside for 10 minutes. Remove from oven, unwrap foil, and cool on counter for 20 minutes. Loosen sides with a buttered knife but keep cheesecake in pan.
Cool cheesecake to room temperature for one hour, then refrigerate for at least 4 hours or overnight to set completely.
Warm heavy cream without boiling. Combine powdered sugar and cinnamon, then gradually whisk in warm cream until smooth and pourable.
Pour cinnamon icing evenly over chilled cheesecake, spread smoothly, and refrigerate longer if needed before slicing and serving.