Preheat the oven to 350°F (175°C) and grease a 9x13-inch baking dish with butter.

Tear Hawaiian rolls into bite-sized pieces and arrange them in the prepared baking dish. Sprinkle optional raisins or chocolate chips.

In a mixing bowl, whisk together eggs, whole milk, heavy cream, granulated sugar, vanilla extract, ground cinnamon, and salt until well-combined.

Pour the custard mixture over the bread pieces, gently pressing down to ensure they are soaked.

Let the mixture sit for 10-15 minutes to allow the bread to soak up the custard.

Bake for 45-50 minutes until the top is golden and firm yet slightly jiggly in the center.

Allow the dish to cool for 15-20 minutes before serving warm or at room temperature.