To a bowl of a stand mixer fitted with a paddle attachment, add the warm milk, room temperature sourdough discard, egg, egg yolk, melted butter and sugar. Mix on low speed until smooth.You can mix and knead this dough by hand.My milk was 110 degrees F. I love using this instant read thermometer to check that the milk isn't hotter than that, otherwise this can kill the instant yeast, which will prevent your dough from rising. If you are using discard from the fridge, add it to the warm milk. Reheat the milk until it reaches 110 degrees F.

To the wet ingredients, add the flour, instant yeast and salt. With the hook attachment, mix again on low speed. Stop to scrap the sides of the bowl to incorporate all the dry ingredients and then continue to mix on low for 1-2 minutes.

Continue to knead the dough on medium speed for 6-8 minutes.You’ll know the dough has been kneaded completely when it is smooth and elastic. The dough will completely pull away from the sides of the bowl and it will pass the windowpane test. You can also knead this dough by hand, but will most likely need to extend the kneading time to 10-12 minutes.

McKenna's Tip: What is the Windowpane Test? This means when you stretch a small section of dough into a thin film, the light will be able to pass through without the dough tearing. If this is accomplished, the dough has been properly kneaded.

Remove the dough and place it in a lightly greased bowl and cover.

Place the dough in a warm place in your kitchen and allow the dough to double in size.In my 70 degree proofing box, this took about 30-45 minutes. The bulk rise greatly depends on the temperature of your dough and kitchen. If you have a colder kitchen or used cooler ingredients, the rise time will take longer. If your kitchen runs warm, the first rise will take less time.

Once the dough has at least doubled in size, punch the top of the dough to remove all the air bubbles. Then, place the dough on a lightly floured work surface.

Gently stretch the dough into a rough rectangle shape. With a bench scraper, divide the dough into 10 equal pieces (about 100g each).

Pull the corners of the dough towards the center, flip, and then roll each piece of dough into a round, tight ball. Place them on a rimmed baking sheet lined with parchment paper. Slightly flatten them. Repeat until all the rolls are shaped.

Once shaped, cover the baking sheet with this plastic cover and let the dough rest for its second rise. The final proof is complete when the burger buns have almost doubled in size and look puffy. This took about 45-60 minutes.

Preheat the oven to 375 degrees F. In a small bowl, whisk together an egg and a splash of water, then brush the top of each bun with the egg wash with a pastry brush. Top with sesame seeds, if desired.

Bake for 13-15 minutes or until the buns are beautifully golden brown and the internal temperature is 190 - 200 degrees F. If the buns are starting to brown too quickly, cover them with aluminum foil and continue to bake.

Remove the Sourdough Buns from the oven and let them cool on a cooling rack. Serve the Sourdough Burger Buns at room temperature with your favorite grilled meat and toppings of choice. Enjoy!