Prep: Preheat oven to 350 degrees F and spray the inside of a 9x13 baking dish with non-stick cooking spray.
Egg Mixture: Place the eggs, creamer, cinnamon, nutmeg, and vanilla in a large bowl. Whisk to combine and set aside.
Cinnamon Rolls: Open each can of refrigerated cinnamon rolls and place each cinnamon roll on a cutting board, set the icing packages off to the side so they can come to room temperature. Use a knife to cut each cinnamon roll into quarters and spread out evenly in the prepared baking dish. Pour the egg mixture evenly over the cinnamon roll pieces in the baking dish.
Brown Sugar: Sprinkle the brown sugar over the top of the casserole, option to add more, if desired.
Bake: Move to the preheated oven to bake for 35-40 minutes, uncovered.
Cool + Icing: Let the cinnamon roll casserole cool slightly. Then drizzle the icing included in the cinnamon roll packages over the top of the casserole. Option to pour it into a bowl and let people add more after serving.
Prep Ahead of Time: This is a great recipe to prep the night before! Simply put it all in the baking dish, cover with plastic wrap or aluminum foil, and then remove the cover and bake the next day. Be sure to reserve the icing packages for adding after baking.
Reheat: Reheat individual pieces in the microwave for 20-25 seconds. Reheat entire baked casserole in the oven at 325 degrees for 20 minutes.