Preheat oven to 350°F (175°C) and grease a 9x13 inch baking pan.

In a medium bowl, beat softened cream cheese and granulated sugar until smooth. Mix in egg and vanilla extract until well combined.

Slice lengthwise through the top of each Hawaiian roll to create a trench for the filling, being careful not to cut all the way through.

Spoon cream cheese mixture into the trenches of each roll.

Brush melted butter evenly over the tops of the filled rolls.

Bake for 20-25 minutes, or until golden brown and filling is set.

Cool slightly in the pan. Dust with powdered sugar or drizzle with glaze if desired.