Preheat oven to 375

Using a mixer, blend together the sugar, cream cheese, vanilla, and yolks

Lay out thawed puff pastry sheet, roll to desired thickness

Spread cream cheese mixture over pastry sheet, roll into a log

Grease circular baking pan with butter

Cut log into half-inch rounds, place cut side up

Brush egg whites over tops of rolls and bake in the oven for 30 minutes or until tops are golden brown. Dust with powdered sugar if desired