Easter Cake with Sour Cream

Description
In Romanian: Pasca cu smantana

Ingredients
Filling:
 * Sweet bread dough.
 * 2 lbs/1 kg sour cream,
 * 3 tablespoons flour,
 * 6 yolks,
 * 3 egg whites,
 * a little vanilla,
 * sugar to taste,
 * salt