Start by preheating your oven to 350°F (175°C) and lightly greasing a 9×13-inch baking dish with melted butter.
Open the cans of cinnamon rolls and set aside the icing — you’ll use it later. Cut each roll into quarters and spread the pieces evenly in the dish.
In a medium bowl, whisk together the eggs, heavy cream, vanilla, cinnamon, and maple syrup. Pour this mixture evenly over the cinnamon roll pieces, making sure everything gets coated. Let it sit for about 10 minutes so the rolls can soak up the liquid.
Bake uncovered for 35–40 minutes, or until the top is puffed and golden brown. If the top browns too quickly, you can loosely cover it with foil during the last 10 minutes of baking.
Remove from the oven and let it cool for about 10 minutes before adding the glaze.
Warm the included cinnamon roll icing slightly in the microwave (10–15 seconds) to make it easy to drizzle. Pour it evenly over the casserole.
