Start by laying your banana on a flat surface with the peel side down. Using a sharp knife, carefully slice lengthwise down the center of the banana, cutting through the peel and into the fruit itself, but stopping just short of cutting all the way through the bottom—you want to create a pocket that holds the fillings without splitting the banana in half. Once sliced, gently open the banana like a book to expose the interior. Sprinkle the pinch of sea salt and ground cinnamon evenly over the exposed banana flesh, which will infuse the fruit as it cooks and complement the sweetness of the chocolate and marshmallows.

Distribute the chocolate chips evenly along the length of the banana's interior, then arrange the miniature marshmallows on top and among the chocolate—I find that miniature marshmallows work so much better than regular ones because they fit snugly in the banana without causing it to split open. Tear off a generous piece of foil (roughly 12 inches long) and carefully wrap it around the prepared banana, folding the edges tightly so no filling can escape during cooking. The foil creates a steam chamber that will melt the chocolate and toast the marshmallows while keeping everything contained.

Place the foil-wrapped banana directly on a grill grate or hold it with tongs 4-6 inches above hot coals or flames, turning occasionally, for about 10 minutes. You're looking for the banana to soften slightly and the chocolate and marshmallows to melt together into a gooey filling—the foil will prevent direct charring while allowing gentle, even heat to do the work. Listen for subtle sizzling sounds and check progress around the 8-minute mark by carefully opening a corner of the foil to peek inside.

Carefully remove the banana boat from the heat using tongs and set it on a heat-safe surface. Peel back the foil and use the graham crackers as edible scoops to dig into the melted chocolate and marshmallow filling, breaking off pieces as needed to grab each spoonful. The warm, gooey filling will soften the crackers slightly, creating the perfect texture—this is truly the best part of campfire cooking, so take your time and enjoy every bite!