Preheat oven to 375°F. Combine sugar and cinnamon in a medium bowl. Set aside.
Place roll dough 1 inch apart on a lightly greased baking sheet; cover and let rise in a warm place, until dough is thawed and doubled in size, about 1 hour.
Cut each roll dough in half. Dip dough halves in melted butter; toss in sugar-cinnamon mixture, and arrange in a lightly greased 12-cup Bundt pan, overlapping slightly. Bake in preheated oven until golden brown, about 25 minutes. Cool in pan 5 minutes; invert onto a wire rack, and cool 15 minutes.
Drizzle top of warm bread with 2 to 3 tablespoons Buttered-rum Syrup. Stir together macadamia nuts and coconut, and sprinkle over bread. Serve immediately with remaining Buttered-rum Syrup.