Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish.
Place the cubed Hawaiian rolls in the prepared baking dish. If using, sprinkle the crushed pineapple and shredded coconut evenly over the top.
In a large mixing bowl, whisk together the eggs, whole milk, heavy cream, granulated sugar, vanilla extract, ground cinnamon, and salt until well combined.
Pour the egg mixture evenly over the cubed rolls, ensuring all pieces are soaked. Gently press down with a spatula to help the rolls absorb the liquid.
Cover the baking dish with aluminum foil and let it sit for 15 minutes to allow the flavors to meld and the rolls to soak up the mixture.
Bake covered for 25 minutes, then remove the foil and bake for an additional 15-20 minutes, or until the top is golden brown and the center is set.
Let the casserole cool for a few minutes before dusting with powdered sugar and serving with warm maple syrup.