Line your pan with parchment paper and grease the parchment paper with cooking spray or a neutral oil. This will ensure the rice krispie treats don't stick to the paper or pan! 2. Once you have fully mixed in all of your add-ins, quickly transfer the mixture to the baking pan. If you wait too long, it becomes too sticky and difficult to work with. 3. Use a 1/3 measuring cup or small glass to flatten the rise krispie treats out into the square pan. 4. Allow them to set at room temperature for at least one hour before cutting. 5. Use a very sharp knife and grease it lightly for easy, clean cuts.