"Dissolve the yeast in the warm water. Melt the butter. Sift the dry ingredients together.In the bowl of an electric mixer, combine the yeast, melted butter, sour cream, vanilla, eggs, and egg yolks. Sift the dry ingredients, add to the yeast mixture, and stir until well blended. Knead with a dough hook or with your hands on a floured board until smooth and elastic. Place in a buttered bowl, cover with plastic wrap, and allow to rise in a warm place until doubled in bulk, approximately 1 hour.Meanwhile, bring milk to boiling point and add poppy seed. Cook for about 5 minutes, stirring carefully, until milk is absorbed. Add sugar or honey. Beat egg thoroughly. Mix1 Tbls. hot poppy seed with the egg and pour into cooked poppy seed. Stir until thick. Add vanilla. Must be cooled before spreading onto the dough.(Dough can be cut in half for two rolls instead).On a floured board, roll the dough into a rectangle approximately 12x 17 inches. Spread the filling evenly on the rectangle, leaving a l-inch margin on the two short sides and one long side. Using a soft pastry brush, wet the margins with water and roll up the rectangle, beginning with the long edge without the margin. Form into a crescent shape, sealing the edges together, and place on a parchment-lined baking sheet. Cover with plastic wrap and allow to rise approximately I hour in a warm place. Preheat the oven to 350 F.Mix egg wash.Just before baking, brush on the egg wash. Using a serrated knife, make decorative slits in the top (optional). Bake for 45 to 60 minutes,(less if cut into two rolls) until deep golden brown. Cool on a rack."