In a large mixing bowl, whisk together the eggs, milk, and vanilla extract until smooth. Add a pinch of cinnamon if desired.

Carefully cut the Hawaiian rolls in half and dip each half into the egg mixture for 30 seconds to 1 minute.

Preheat a non-stick skillet over medium heat and melt the butter to coat the surface.

Place the soaked rolls cut-side down in the skillet and cook for 3-4 minutes until golden brown. Flip and cook for another 3-4 minutes.

Remove from skillet and serve immediately, dusting with powdered sugar and offering fresh fruit or maple syrup on the side.