Dissolve yeast and sugar in 1/2 cup warm water.
In another bowl, whisk together flour and salt.
Add yeast mixture, eggs, buttermilk and butter to bowl of stand mixer fitted with bread hook.
Mix at low speed.
Slowly add the flour and salt a little at a time. Knead until dough begins to pull away from the sides for the bowl.
Once dough begins to pull away from the sides of the bowl, knead for an additional 5 minutes.
Place dough in a greased bowl, cover and let rise in a warm place until doubled, about 1 hour.
Punch down risen dough.
Place on floured board and divide into 8 equal portions.
Roll each portion into a rectangle.
Brush melted butter over one rectangle and lay another rectangle on top. Roll the two rectangle into a cylinder.
Repeat with remaining balls of dough. You should have four cylinders when done.
Cut off the ends of the cylinder. Cut middle of the dough into four triangles. Make a diagonal cut in the center, and then make a diagonal cut in the other direction to create triangles.
Put one end of a cylinder, cut side down in the center of a greased cookie sheet. Arrange the remaining ends around the center.
Pick up the cylinders of dough as if they are still in one pieces and arrange around the center bouquet.
Cover and let rise until doubled rise in warm place for about 30 to 40 minutes.
Beat egg yolk and milk. Brush over dough.
You may sprinkle poppy seeds or sesame seeds on top at this point if you wish.
Bake bread in a preheated 350° oven for 30 -40 minutes.
If bread is not browned as you would like, set the oven to broil with bread on middle rack for 3-5 minutes. Watch closely! It can get too brown quickly.
Brush bread with melted butter as soon as it is done, and let cool for 10 minutes before eating.
So fun to break off a uniquely shaped roll!