To prepare this homemade hamburger buns recipe, start by making the dough. Add in the mixer's bowl the yeast, the warm water and 50g flour (5 tbsps). Using a hand whisk, whisk all the ingredients to form a batter. Wrap the bowl with plastic wrap and set aside for 6-7 minutes, until the yeast rises and starts bubbling.
In the meantime melt the butter at very low heat. The butter should be at the same temperature as your finger. If it is warmer, leave to cool down for a few minutes.
Pour the butter in the yeast mixture and add the egg and sugar. Whisk to combine. Top with the flour and add the salt.
Using the dough hook mix at first at low speed, until the ingredients start to combine and then mix at medium-high speed for about 10 minutes, until the dough doesn't stick on the sides of the bowl.
Coat lightly the dough with oil and place in a large bowl. Cover with plastic wrap and let the dough rise in a warm place for about 2 hours or until doubled in size.
Gently deflate the dough and divide in 8 equal sized pieces (approx. 115 g./4 oz. each). Form each piece into a round shape and pat into flat disc shapes about 1.5 cm thick.
Arrange on a parchment-lined baking tray, cover with plastic wrap and let rise for about 1 hour or until doubled in size.
Preheat the oven to 180C. Brush tops with egg wash (beaten egg and milk) and sprinkle with sesame seeds. Bake for 16-17 minutes until nicely colored.