1. Preheat your oven to 350F / 180C.
2. Line a baking sheet with parchment paper (Do not try anything else)
3. I used Cracker Barrel Slices.
4. Cut sandwich slices into 4 equal-sized pieces and place them onto the parchment, a couple of inches apart.
5. I only placed 12 on a tray as they spread as they bake.
6. Bake for ±10 minutes or until beginning to brown around the edges, depending on your own oven.
7. Leave them on the tray for ±5 minutes, to set a bit, before gently scooping them up with a plastic or metal egg-lifter and placing them on a cold surface or plate, and allow to cool completely, to finish getting crispy.

Some additional info:

1. Please note that as each oven differs, you may have to bake it a little bit longer to get it nice and crispy.
2. Another factor would be the amount of fat/oil in your cheese.
3. Source: Saw this idea on the internet, and could not find the recipe again, so just winged it. Made it from memory from way back then, so this will not resemble the original recipe in any way shape, or form.