• Preheat the oven to 350°F. Grease a 9x12 inch baking dish with butter or nonstick spray. Tear 1 12-count package Hawaiian rolls into bite-sized pieces and spread evenly in the dish.
  1 12-count package Hawaiian rolls
• In a large bowl, whisk together 6 large eggs, ½ cup heavy cream, ⅓ cup brown sugar, and 1 teaspoon cinnamon until smooth.
  6 large eggs, ½ cup heavy cream, ⅓ cup brown sugar, 1 teaspoon cinnamon
• In a small bowl, toss 1 cup blueberries with 1 tablespoon lemon juice and 1 tablespoon flour to help prevent sinking.
  1 cup blueberries, 1 tablespoon lemon juice, 1 tablespoon flour
• Sprinkle the blueberries over the torn rolls. If using cream cheese, tuck the 4 ounces cream cheese throughout the bread and berries. Pour the custard evenly over the top and gently press the bread down so it soaks up the custard.
  4 ounces cream cheese
• Cover with foil and bake for 35 to 40 minutes. Remove foil and bake another 10 minutes, until golden and set in the center.

Cool slightly and glaze

• Let the casserole cool for 5 to 10 minutes. In a small bowl, whisk together 1 cup powdered sugar, 5 tablespoons milk, 1 teaspoon vanilla extract, and lemon zest (if using). Drizzle over the warm casserole.
  1 cup powdered sugar, 5 tablespoons milk, 1 teaspoon vanilla extract, lemon zest