Preheat the oven to 400 degrees F (200 degrees C). Grease a 9x5-inch loaf pan.

Mix sugar and cinnamon together in a bowl.

Set icing packet aside. Cut cinnamon rolls into quarters. Dip pieces in melted butter, coat in cinnamon-sugar, and place in the prepared pan.

Bake in the preheated oven until dough has risen and top is golden brown, 20 to 25 minutes; drizzle icing over top and let cool in the pan for 5 minutes. Turn the monkey bread out onto a plate and serve warm.