Preheat oven to 325°F (163°C) and grease a 9-inch springform pan. Set aside.

In a bowl, mix graham cracker crumbs, melted butter, granulated sugar, and ground cinnamon until fully combined. Press into the bottom and sides of the springform pan.

Bake crust for 8–10 minutes. Remove and allow to cool completely.

In a large bowl, beat softened cream cheese until smooth. Add granulated sugar and beat until incorporated.

Add sour cream, eggs, vanilla extract, and cinnamon. Mix on low speed until just combined. Avoid overmixing. Pour mixture over cooled crust.

Prepare cinnamon swirl by mixing melted butter, brown sugar, and cinnamon. Transfer to a piping bag or resealable bag with one corner cut.

Pipe mixture in a spiral on top of the batter. Use a skewer to lightly swirl into the cheesecake.

Bake for 55–65 minutes until center is set but slightly jiggly. Turn off oven, crack the door, and let it cool inside for 1 hour.

Let cheesecake cool to room temperature, then refrigerate at least 4 hours or overnight.

For the glaze, whisk together powdered sugar, milk, and vanilla until smooth. Drizzle over the chilled cheesecake in a spiral pattern before serving.