Plug in a 6-quart oval slow cooker and set it to Low.
Line the bottom of the crock with a large piece of parchment paper and coat the parchment with nonstick cooking spray.
Put the graham crackers in a food processor and pulse until they are fine crumbs. Add the melted butter and pulse until the crumbs are evenly moistened.
Pour the crumb mixture into the lined crock and press it evenly and firmly over the bottom to form a crust (use the bottom of a measuring cup or a spoon to press).
Wipe out the food processor bowl. Add the cream cheese and the granulated sugar and pulse until smooth and lump-free. Scrape down the bowl as needed.
Add the sour cream, eggs, flour, vanilla extract, and salt to the processor and puree until the filling is very smooth and homogenous.
Pour the filling over the crust in the crock and smooth the top with a spatula.
Cover the slow cooker and cook on Low for 5–7 hours, until a skewer or toothpick inserted into the center comes out clean. If condensation collects on the underside of the lid during cooking, carefully wipe it with a clean towel (take care to avoid burns and to keep heat in the cooker).
When the cheesecake is done, remove the lid, then move the entire crock to the refrigerator and chill for at least 3 hours.
After chilling, carefully lift the cheesecake out of the crock using the edges of the parchment paper. Peel the paper away, slice, and serve.