In a large mixing bowl, whisk together the eggs, milk, vanilla extract, cinnamon, and sugar until well combined.
Preheat a large skillet or griddle over medium heat and add a tablespoon of butter, allowing it to melt and coat the surface.
Dip each half of the Hawaiian rolls into the egg mixture, ensuring both sides are well soaked but not overly soggy.
Place the soaked rolls onto the skillet or griddle and cook for about 2-3 minutes on each side, or until golden brown and slightly crispy.
Repeat with remaining rolls, adding more butter to the skillet as needed.
Serve warm with maple syrup drizzled on top and a dusting of powdered sugar if desired.