Sprinkle yeast over warm water and let sit until foamy, about 5 minutes.
Meanwhile, combine flour, sugar, and salt in a large bowl.
Once your yeast mixture is foamy, add in butter and egg (combine in the bowl of a stand mixer using a dough hook or other large bowl). Slowly add in flour mixture, kneading until the dough is smooth and soft.
Cover the dough, and let it rise for 1 to 2 hours, or until it's nearly doubled in bulk.
Gently deflate the dough, and divide it into 8 pieces. Shape each piece into a round ball; flatten to about 3" across. Place the buns on a lightly greased or parchment-lined baking sheet, cover, and let rise for about an hour, until noticeably puffy.
If you want to add seasame seeds, Brush the buns with a whisked egg white and sprinkle the seeds on top.
Bake the buns in a preheated 375°F oven for 15 to 18 minutes, until golden. Remove them from the oven, and brush with melted butter, if desired.
Cool the buns on a rack.
Yield: 8 large buns.
Recipe by Kitchen Meets Girl at https://kitchenmeetsgirl.com/homemade-hamburger-buns/