In a large skillet, combine the brown sugar, lime juice, butter, cinnamon and allspice, cooking until thick and bubbly, stirring often. Add the bananas and cook until soft, about 4 minutes. Add the liqueur and rum, flaming carefully if desired. Let the fire burn out.
Place 1 macaroon on each of 6 dessert plates; top with a scoop of vanilla ice cream. Spoon the hot bananas and sauce over the ice cream and macaroons.
Makes 6 servings