This recipe comes from a book I have called Pofta Buna - the Romanian Way of Cooking. It's for a pastry (Lichiu), but basically like a Colak. I hope it's the one you want.

KOLACKI (COLAC)

Basic Sweet Dough (recipe follows)
FOR THE FILLING:
3 pkg (8 oz each) cream cheese
1/2 lb. brick cheese, grated
1 1/2 cups sugar
6 egg yolks
1/2 tsp salt
6 egg whites (stiffly beaten?)

Prepare the basic sweet dough (below). Roll 1/4-inch thick and place in a greased medium size pan.

Cover with filling made by blending cheeses, sugar, egg yolks and salt together. Gently fold in whites.

BASIC SWEET DOUGH

This is a basic sweet dough on which you put the above.

3/4 cup milk
6 tbsp butter
6 tbsp sugar
1 1/2 pkg dry yeast
2 to 3 tbsp lukewarm water
2 eggs well beaten
3 cups all purpose flour
1/2 tso salt

Scald milk, add butter and sugar. Let stand until lukewarm.

Add yeast to lukewarm water and let stand 10 minutes.

Add beaten eggs to milk mixture, then blend in yeast.

Sift flour and salt and beat into milk and egg mixture. Beat with wooden spoon until spoon and bowl are clean and not sticky. Place dough in greased bowl and cover with clean cloth. Set in pan of warm water until dough rises to more than double in bulk.

Then flatten out dough with hands to fit into baking pan - dough should be about 1/2-inch thick. Spread with filling.

Bake in 375 degree F oven for 25-30 minutes.