Hedeg Kilet (Nut/Poppyseed Roll)

Why I Love This Recipe
I think this is Humgarian. At least, it is Slavic. Times do no include overnight refrigeration. The number of servings is a guess. There are 2 fillings here: one is poppy seed from a can, the other is a walnut filling.
Ingredients You'll Need
DOUGH
1 teaspoon yeast
1/4 cup lukewarm milk
1 teaspoon sugar
1 tablespoon flour
1/2 lb melted butter
1 cup cream or half-and-half
4 egg yolks, beaten
3/4 teaspoon salt
1 tablespoon sugar
4 cups flour
canned poppy seed filling (optional)
WALNUT FILLING
1 lb ground walnuts
1/2 cup sugar
1/2 cup warm milk
2 tablespoons melted butter
FILLING:.
Mix all ingredients together to form a paste.
Spread with filling.
Sprinkle with butter; roll into loaves as for a jelly roll; let stand 2 hours.
Brush with egg white slightly beaten.
Bake for 35 minutes.
Directions
Dissolve yeast in lukewarm milk; add 1 teaspoon sugar and 1 tablespoon flour; set aside.
Melt butter; add 1/2 and 1/2 cream and beaten egg yolks; add this mixture to the yeast mixture.
To the combined mixture add salt, 1 tablespoon sugar and flour; mix together, and divide into 4 parts.
Put in refrigerator overnight.
Oven at 375ºF.
Roll each part 1/2 inch thick.
16 servings
3 hours
2¼ hours prep