Preheat the oven: Set your oven to 325°F (163°C) and prepare a muffin pan by lining each cup with liners.
Make the crust: In a bowl, combine 1 1/2 cups graham cracker crumbs, 1/4 cup granulated sugar, 1/2 tsp ground cinnamon, and 6 tbsp melted unsalted butter. Mix well until the crumbs are evenly coated. Press this mixture firmly into the bottom of each muffin liner. Bake in the preheated oven for about 5 minutes, then remove and allow to cool.
Prepare the cheesecake filling: In a large mixing bowl, beat 16 oz softened cream cheese with 1/2 cup granulated sugar until smooth and creamy. Add 1 tsp vanilla extract, 2 large eggs (one at a time), 1/4 cup sour cream, and 1/4 cup heavy cream. Mix well until the filling is completely combined.
Fill the crusts: Pour the cheesecake batter into the cooled crusts, filling each approximately two-thirds full.
Create the cinnamon swirl: In a separate bowl, mix 1/4 cup packed light brown sugar, 1/2 tsp ground cinnamon, and 1 tbsp melted unsalted butter. Dollop this mixture over the tops of the batter and gently swirl it with a toothpick or a knife to create a marbled effect.
Bake: Place the muffin pan back in the oven and bake for 15-20 minutes, or until the cheesecakes are set around the edges but slightly jiggly in the center.
Cool and refrigerate: Let the cheesecakes cool to room temperature, then refrigerate for at least 2 hours before serving to set fully.
Prepare the glaze: In a small bowl, whisk together 1/2 cup powdered sugar and 2-3 tsp milk until smooth. Drizzle this glaze over the chilled cheesecakes before serving.