Bundt cakes usually stick because the pan wasn't properly prepared, or they were left to cool too long. Here's how to properly grease and flour your pan to keep it from sticking. Grease the pan with butter or a light coating of nonstick cooking spray. Put a couple tablespoons of flour in it, then tap and turn the pan to coat the inside with flour. Tap out the excess. Alternatively, spray the pan with a baking spray that has flour in it.