Preheat your campfire or coals: you want a steady bed of hot embers, not tall flames. If using a camp stove oven, set to 350°F (175°C).
In a large bowl, mash the bananas with a fork until smooth. Stir in the melted butter, sugar, egg, and vanilla.
Add the flour, baking soda, and salt directly to the bowl. Stir just until combined—no streaks of flour remain. Fold in the chocolate chips.
Grease a 9x5-inch loaf pan or line it with parchment. Pour in the batter and spread evenly. Sprinkle a few extra chocolate chips on top if you like.
Place the pan inside a Dutch oven set on a few hot coals. Cover the Dutch oven and arrange coals on the lid: about 8 coals on bottom, 14 on top for a 12-inch oven. Rotate the oven and lid in opposite directions every 15 minutes.
Bake for 40-50 minutes, until a skewer inserted in the center comes out clean. Let cool in the pan for 10 minutes, then turn out onto a plate or cutting board.
Slice and serve warm. Store leftovers in a sealed container—it keeps well for a day or two at camp.
