Prepare the slow cooker: place a large piece of parchment paper in the bottom of a 6-quart oval slow cooker and coat the paper with nonstick cooking spray.
Make the crust: place graham crackers in a food processor and pulse into fine crumbs. Add the melted butter and pulse until combined.
Press the crumb mixture evenly into the bottom of the prepared slow cooker to form the crust.
Clean the food processor bowl, then add the cream cheese and granulated sugar and pulse until smooth.
Add the sour cream, eggs, all-purpose flour, vanilla extract, and salt to the cream cheese mixture and puree until the filling is very smooth.
Pour the filling over the crust in the slow cooker and smooth the top with a spatula.
Cover and cook on low for 5–7 hours, or until a skewer inserted into the center comes out clean; wipe any moisture from the lid during cooking to prevent drips onto the cheesecake.
Chill: transfer the crock to the refrigerator and chill the cheesecake for at least 3 hours. Lift the cheesecake out by the parchment, peel off the paper, slice, and serve.