1. Prepare the Dough: In a large mixing bowl, combine the active sourdough starter, warm water, sugar, and salt. Stir until the starter is mostly dissolved. Gradually add the bread flour, mixing with a wooden spoon or your hands until a shaggy dough forms. Turn the dough out onto a lightly floured surface and knead for about 5-7 minutes until it’s smooth and elastic.

2. First Rise (Bulk Fermentation): Lightly grease your large mixing bowl with olive oil. Place the kneaded dough in the bowl, turning it once to coat. Cover the bowl tightly with plastic wrap or a damp kitchen towel. Let the dough rise at room temperature (around 70-75 F) for 8-12 hours, or until it has doubled in size. This can also be done overnight.

3. Divide and Shape the Bowls: Gently punch down the risen dough to release the air. Turn it out onto a lightly floured surface. Divide the dough into 4-6 equal pieces, depending on your desired bread bowl size. For each piece, gently form it into a tight ball by pulling the edges underneath and pinching them together at the bottom.

4. Second Rise (Proofing): Lightly dust a baking sheet with cornmeal (if using) or line it with parchment paper. Arrange the shaped dough balls on the prepared baking sheet, leaving ample space between them. Cover loosely with plastic wrap or a damp towel and let them rise in a warm spot for 2-4 hours, or until they look visibly puffy and have increased in size by about 50%.

5. Preheat Oven and Score: About 30 minutes before baking, preheat your oven to 425 F (220 C). If you have a baking stone or Dutch oven, place it in the oven to preheat as well. Just before baking, use a sharp knife or a bread lame to score the top of each dough ball with a simple “X” or a few parallel lines. This helps the bread expand evenly.

6. Bake the Bread Bowls: Carefully transfer the baking sheet to the preheated oven. If using a baking stone, you can slide the bread bowls directly onto it. Bake for 30-35 minutes, or until the crust is deeply golden brown and sounds hollow when tapped on the bottom. For an extra crispy crust, you can place a pan of hot water on the bottom rack of your oven during the first 15 minutes of baking to create steam.

7. Cool and Hollow Out: Once baked, transfer the bread bowls to a wire rack to cool completely. This is crucial for the internal structure to set. Once cool, use a serrated knife to carefully cut a lid off the top of each bread bowl. Scoop out the soft interior bread, leaving a thick crust (about 1/2 to 3/4 inch thick) to hold your soup. Reserve the scooped-out bread for dipping or croutons.