Preheat your oven to 325 degrees F (163 degrees C).

In a mixing bowl, combine graham cracker crumbs, granulated sugar, and ground cinnamon. Pour in melted unsalted butter and stir until the texture resembles wet sand. Press evenly into the bottom of a 9-inch springform pan. Bake for 8 to 10 minutes and then allow to cool completely.

In a medium bowl, combine the sliced peaches, brown sugar, ground cinnamon, cornstarch, and lemon juice. Toss until the peaches are well coated and set aside for 10 minutes.

In a large mixing bowl, beat the softened cream cheese until smooth. Gradually mix in granulated sugar until creamy. Blend in eggs, one at a time. Add in vanilla extract, sour cream, and all-purpose flour until just combined.

Pour half of the cheesecake batter over the cooled crust. Add the peach mixture on top, spreading it evenly. Pour the remaining cheesecake batter over the peaches and arrange any extra peach slices if desired.

In a separate bowl, combine all-purpose flour, brown sugar, ground cinnamon, and salt. Cut in cold butter until the mixture resembles coarse crumbs. Sprinkle this streusel mixture generously over the cheesecake.

Bake in a preheated oven for 55 to 65 minutes, until the edges are set but the center still has a slight jiggle.

Turn off the oven, crack the door open, and let the cheesecake cool inside for 1 hour. After cooling, refrigerate for at least 4 hours before slicing.