Preheat your oven to 325°F (163°C). In a medium bowl, mix together graham cracker crumbs, granulated sugar, melted unsalted butter, and ground cinnamon until well combined. Press this mixture firmly into the bottom of a 9x13-inch baking dish. Bake for 10 minutes, then remove to cool.

In a large mixing bowl, beat the cream cheese until smooth and creamy. Gradually add granulated sugar, mixing thoroughly after each addition. Incorporate the eggs one at a time. Finally, blend in the vanilla extract, sour cream, and flour until silky.

Pour the cheesecake filling over the cooled crust, spreading evenly. Bake at 325°F (163°C) for 40-45 minutes. The edges should be set while the center remains slightly jiggly. Allow to cool on a wire rack.

After 30 minutes on the rack, transfer the cheesecake to the refrigerator. Chill for at least 2 hours to firm up the filling.

Slice the ripe peaches into thin wedges. In a small saucepan, combine peach preserves, water, and optional lemon juice. Heat over medium until melted and smooth, stirring until well combined.

Once chilled, arrange the peach slices over the top and drizzle the warm glaze generously for a glossy finish. Cut into bars for serving.