Sourdough hamburger buns just add an extra oomph of flavor to any burger with that signature sourdough taste and light nuttiness from sesame seeds on top!
In the bowl of your stand mixer, add the sourdough starter, oil, milk, and egg. Beat to combine.
Add the salt, sugar, and 2 cups of flour.
Mix with the dough hook on low speed for 3 to 5 minutes, until the dough comes together well but still sticks to the bottom of the bowl.
Dust a work surface well with flour, and remove the dough from the bowl onto the work surface.
Knead the dough lightly until it's soft but not overly sticky.
Form the dough into a smooth ball.
Lightly spray the mixing bowl with cooking spray, and return the dough to the bowl. Cover the bowl tightly with plastic wrap or a damp kitchen towel.
Let the dough rest at room temperature 2 to 6 hours, depending on your timing.
After the dough has rested, remove it from the bowl and divide it into 8 pieces.
Form each piece into a round ball, and place on a baking mat or parchment-lined baking sheet, about 2 inches apart. Gently use the palm of your hand to press the dough so that it's 1 to 1.5 inches thick. This will help it be more bun-shaped when it cooks.
Cover the dough lightly, and let it rest for 30 minutes or so while the oven preheats.
Heat the oven to 400 degrees F. When the oven is hot, brush the top of the bun with 1 egg white beat well with 1 tablespoon of water, and then sprinkle the wet tops with sesame seeds.
Bake until the buns are golden-brown, about 15 minutes.
Remove from the oven, and let the buns cool 10 to 15 minutes minimum before slicing in half and serving with your favorite burger, pulled pork, or just about any other sandwich toppings.
Notes
This makes 8 medium-sized buns. If you'd like large buns, divide the dough into 6 and make 6 large buns, or divide it into 12 to make slider-sized buns.