Prep the Dough
In a small bowl, mix warm water, 1 tsp sugar, and yeast. Let sit for 5-10 minutes until foamy.
In a large bowl, mix flour, remaining sugar, and salt.
Add the foamy yeast mixture, warm milk, melted butter, and egg to the dry ingredients.
Mix until dough forms. It will be slightly sticky.
Knead and Rise
Knead dough on a floured surface for 5-8 minutes until smooth and elastic.
Place in an oiled bowl, cover, and let rise in a warm place for about 1 hour, or until doubled in size.
Shape the Buns
Punch down dough to release air.
Divide into 8-10 pieces and roll each into a 6-inch log.
Flatten slightly and place on a parchment-lined baking sheet.
Cover loosely and let rise for 30-45 minutes until puffy.
Add Poppy Seeds and Bake
Preheat oven to 375°F.
Brush tops with egg white mixture.
Sprinkle generously with poppy seeds (and coarse salt if using).
Bake for 15-18 minutes until golden brown and hollow-sounding when tapped.
Cool on a wire rack for at least 20 minutes before slicing.