Preheat oven to 375°F. Separate strips of bacon & lay out flat in single layer on lightly sprayed, foil-lined rimmed baking pan, gently stretching each strip by an inch or two. Bake for 10-12 minutes or until bacon begins to curl & edges just starting to crisp, rotating pan halfway through cooking. Remove bacon from pans with spatula while warm, draining briefly on absorbent paper & reserve.
Cut bacon slices in half crosswise & tightly wrap around marshmallows, securing with skewer or roasting stick. Roast marshmallows over campfire until toasty brown on the edges, being careful to not burn or ignite your marshmallows!
Immediately sandwich roasted marshmallows between two graham crackers with a piece of chocolate & eat hot from the fire!