To begin, gather all the ingredients and have them close by on the counter or table, ready to use.
Prepare the Starter
In a large mixing bowl, combine the active sourdough starter, water, and 3 cups of all-purpose flour. Beat vigorously with dough whisk for 1 minute. Cover with plastic wrap and let rest at room temperature for 2-3 hours. Refrigerate overnight.
Make the Dough (Second Day)
The next day, remove the dough from the refrigerator and allow it to come to room temperature, about an hour.
In a large mixing bowl using a kneading hook attachment, combine the starter mixture with the remaining 2 cups all-purpose flour, granulated sugar, kosher salt, and optional instant yeast. Begin mixing at a low speed, adding up to 1/4 cup of water as needed to make a smooth dough. Adding water may, or may not be necessary. Continue kneading for 5-7 minutes.
Transfer dough to a large greased bowl and cover with plastic wrap. Allow the dough to rise until it has doubled. (This may take 2-3 hours).
If you have opted not to use the instant yeast, you may remove the dough at each hour interval to stretch and fold, envelope-style to work the gluten in the dough. The dough will most likely be sticky. Use a stainless bench scraper to lift the dough from the work space more easily.
Form the Dough into Bowls
Preheat oven to 425 degrees along with a baking stone. Place 2 sheets of parchment paper on a work surface and spray with baking spray. If you do not have a baking stone, you may use two baking sheets lined with parchment paper or a silicone baking mat.
Once the dough has doubled, stretch and fold the dough, envelope-style, again using the bench scraper as needed.
Divide the dough into 8 equal pieces, forming each into a ball. Place four balls on each sheet of parchment paper and cover with greased plastic wrap or a clean cotton tea towel. Allow the dough to rise for 40-60 minutes until puffy.
Prepare the Dough for Baking
In a small bowl, prepare your egg wash by whisking together one small egg with 2 tablespoons water.
Uncover the dough. Using a pastry brush, brush each ball with egg wash. Then sprinkle each with sesame seeds or Everything Bagel Topping.
Using kitchen shears, cut parchment paper into squares for each of the dough balls. With a pizza peel, transfer each square to the baking stone, four at a time. Bake until golden brown on top, approximately 20-24 minutes. Repeat baking procedure with the remaining bowls.
Transfer bread bowls to wire racks to cool completely. This recipe will make 8 bread loaves.