Preheat the oven to 220C/Gas 7 or prepare barbecue grill.
1) Cut off the ends of the bananas. Place the unpeeled bananas on an ungreased baking tray dish, or place the bananas on the lightly oiled rack of barbecue grill. Bake or grill for 15 minutes, or until the skins burst and turn black. Discard the skins and cut the bananas lengthwise.
2) Mix the butter, brown sugar, and lemon and drizzle over the cooked bananas. Serve with ice cream.