01 - Preheat the oven to 350°F and lightly grease a 9x13-inch baking dish.
02 - Distribute the cubed cinnamon rolls evenly within the prepared baking dish.
03 - In a large bowl, whisk together the whole milk, heavy cream, eggs, granulated sugar, brown sugar, vanilla extract, ground cinnamon, nutmeg, and salt until smooth.
04 - Pour the custard mixture evenly over the cinnamon roll cubes, gently pressing down to ensure full absorption.
05 - Allow the dish to rest for 10 to 15 minutes so the cinnamon rolls can soak up the custard.
06 - Bake for 35 to 40 minutes until the surface is golden and the custard is set but slightly jiggly in the center.
07 - While baking, whisk together powdered sugar, milk, and vanilla extract in a small bowl until smooth and pourable.
08 - Remove from oven and let cool for 10 minutes before drizzling the icing on top.