01 - Preheat oven to 350°F and grease a 9x13 inch baking dish.
02 - Open cinnamon roll cans, reserve icing, and cut each roll into quarters. Arrange pieces evenly in the baking dish.
03 - Whisk eggs, whole milk, heavy cream, vanilla extract, ground cinnamon, sugar, and salt in a bowl until smooth.
04 - Pour custard evenly over cinnamon roll pieces, pressing lightly to ensure coverage.
05 - Drizzle melted butter and maple syrup over the custard-soaked rolls.
06 - Bake for 30 to 35 minutes until puffed, golden, and a knife inserted in the center comes out clean.
07 - Let casserole rest for 10 minutes, then drizzle with reserved icing before serving warm.