Place a grill or grate that’s higher than the flames of a campfire or cook over the still-hot embers of a campfire. Alternatively, preheat BBQ to medium heat (350°F; 177°C) (see Chef’s Tips).
In a small bowl, combine the Redpath® Demerara Style Sugar, ground cinnamon, and salt. Mix well to combine.
Cut 4 12-inch (30 cm) pieces of heavy-duty aluminum foil or 8 pieces of regular aluminum foil doubled up.
Cut bananas with the skin on, in half, lengthwise. Place two banana halves, cut side up, onto one of the prepared pieces of parchment and foil. Sprinkle the halves with ¼ of the Brown Sugar mixture, patting the sugar onto the cut sides to evenly cover. Drizzle with 2 teaspoons (10 ml) of the dark rum and 2 teaspoons (10 ml) of the banana liqueur, if using. Dot 1 tablespoon (14 grams) of butter over both halves.
Bring up the two sides of the foil, meeting the edges together. Carefully fold the edges down, creating a tight foil packet against the sides of the banana. However, do not allow the foil to touch the fillings of the banana; stop about 2 inches above the fillings, forming a slight tent over the top of the banana halves. Twist and/or fold the ends of the foil to fully seal in the banana to prevent any of the fillings from seeping out.
Repeat steps 4–5 with the remaining bananas and filling.
Place the foil-covered bananas onto the hot grate and/or nestle them into the hot embers of a campfire, ensuring that the cut side (seam of the packet) is pointing up. Heat for 10 minutes or until bananas give a little when gently squeezed with a pair of tongs. If the bananas are still firm, add 2 to 3 minutes to the cooking time.
Remove from the fire with a pair of tongs. Unwrap bananas, being careful of the hot steam escaping from the packet.
Serve warm, topped with vanilla ice cream.