First, open the canned cinnamon rolls and sit the icing to the side. Then slice the cinnamon rolls into quarters. Place them all in the baking dish.
In a bowl, combine the eggs, half and half and the cinnamon. Pour this mixture over the cut cinnamon rolls. Toss everything together to make sure all the cut pieces come in contact with the eggs. Cover the dish and allow to sit in the fridge for 2 hours or even better overnight.
Preheat the oven to 375℉.
Place the uncovered baking dish into the oven and cook for 25 minutes. When you pull them from the oven, cover them with the icing and spread it while they are super hot.
Allow the cinnamon roll casserole to cool before serving.