Mix water, yeast and 1 cup flour together. Let sit for 10 minutes until mixture becomes bubbly. Mix in remaining ingredients except for sesame seeds and egg wash. Always start with the lower amount of flour. Continue adding the remaining flour as needed.
Knead in a stand mixer for 5 minutes, or for 10 minutes by hand.
Cover and let rise until doubled.
Gently deflate and divide dough in half. Working with one half at a time, divide into thirds and then each into thirds again.
Each original half will be cut into 9 equal pieces.
Roll each piece into a round shape.
Place on a baking sheet covered with parchment paper, or lightly sprayed with a non-stick spray. After placing on sheet, gently press down on the top to create the hamburger bun shape. I usually let the buns rest for a couple of minutes and then press again. They seem to give a bit more and also hold their shape better.
Cover and let rise again for 30 minutes.
Use a pastry brush and brush buns with the egg wash. Sprinkle sesame seeds across the top.