**Prepare the Crust:** Preheat your oven to 325°F (165°C). Mix graham cracker crumbs, sugar, cinnamon, and melted butter in a bowl. Press the mixture into the bottom of a springform pan. Bake for 8 minutes, then let cool.
**Make the Filling:** In a large bowl, beat the cream cheese and sugar until smooth. Add sour cream and vanilla, mixing well. Beat in eggs one at a time.
**Create the Cinnamon Swirl:** In a small bowl, mix flour, cinnamon, and brown sugar. Stir 1/3 of this mixture into the cheesecake batter.
**Assemble the Cheesecake:** Pour half of the batter over the crust. Sprinkle half of the remaining cinnamon-sugar mixture over the batter. Repeat with the remaining batter and cinnamon-sugar mixture, creating a swirl effect with a knife.
**Bake:** Place the pan in a water bath and bake for 50-60 minutes, or until the center is set. Turn off the oven and let the cheesecake cool inside for 1 hour. Refrigerate for at least 4 hours or overnight.
**Make the Glaze:** Whisk powdered sugar, milk, and vanilla together until smooth. Drizzle over the cooled cheesecake before serving.