If using a flexible silicone mold to set the jello shots, prepare it by spraying lightly with cooking spray. Then wipe out each mold cavity thoroughly with a paper towel. This will leave a very slight residue which will aid in unmolding without affecting the taste or appearance of your jello shots. A glass or non-reactive metal standard 1 lb loaf pan, or two mini loaf pans, may also be used to set the jello shots. No prep needed for a pan.