- 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 chopped pecans evenly over the rolls. 
- In a large mixing bowl, whisk together the eggs, 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 on the rolls to help them absorb the liquid. 
- Cover the baking dish with aluminum foil and let it sit for about 15 minutes to allow the rolls to soak up the mixture. 
- Bake in the preheated oven for 25 minutes covered, then remove the foil and bake for an additional 15-20 minutes, or until the top is golden brown and the center is set. 
- Remove from the oven and let it cool for a few minutes before serving. Dust with powdered sugar and serve with maple syrup if desired.