In a medium saucepan over medium heat, combine pitted cherries, white granulated sugar, and cornstarch. Stir until bubbling and thickened, about 5-7 minutes. Mash half of the cherries for texture, let cool.

Preheat your oven to 325°F (163°C). Crush Oreo cookies into fine crumbs and mix with melted butter. Press into a 9-inch springform pan and bake for 10-12 minutes. Allow to cool.

In a large mixing bowl, beat softened cream cheese and white sugar with an electric mixer until smooth. Add sour cream, cherry purée, and vanilla extract, mixing until combined. Incorporate eggs one at a time on low speed.

Pour cheesecake filling over the cooled Oreo crust. Prepare a water bath and bake for 70-80 minutes until edges set and center jiggles slightly.

Turn off the oven and crack open the door, allowing the cheesecake to cool in the oven for 30 minutes. Move to a wire rack to cool completely before refrigerating for at least 6 hours.

Remove cheesecake from the springform pan and top with reserved cherry mixture before serving. Slice and enjoy chilled.