Sift 4 cups of flour in to a large bowl. Add in 2 packs of yeast.
Cut in 1 cup of soft butter. A dash of salt. In another bowl mix
together 3 egg yolks, 1/2 cup of sour cream and teaspoon vanilla.
Add this mixture to the flour. Knead dough till a good consistency
is achieved. Divide in to 2 equal part, place in to wax paper
and put in to fridge. When time roll in to a rectangle and spread
and top with a fork. Brush the roll with a egg whites and water
mixture (with some sugar in it) Bake at 350 for 30-45 minutes.