Proof the Yeast (Active Dry): In a large bowl, whisk the yeast and sugar (if using) into the lukewarm water. Now, let it sit for 5-10 minutes until foamy.

Combine: Add the flour and salt to the wet mixture. And use a wooden spoon or rubber spatula to mix until the flour is just absorbed and the dough forms a very sticky, shaggy ball. And do not knead or overmix.

Rest: Lightly coat the dough with olive oil and cover the bowl tightly with plastic wrap or a damp towel.

Rise: Let the dough rest in a warm, draft-free spot for 1.5 to 2 hours or until it has doubled in size and has visible bubbles. (For a deeper flavor, this step can be done in the refrigerator for 8-12 hours).

Prep Bowl: Generously grease your oven-safe baking vessel(s) (e.g one Dutch oven or two 1-quart Pyrex bowls) with butter or olive oil.

Deflate & Shape: Gently turn the dough out onto a lightly floured surface. Now, using floured hands, gently pat the dough into a rough round and lightly fold the sides in toward the center a few times. (If making two small loaves, divide the dough in half with a sharp knife or two forks).

Transfer: Place the dough, seam-side down, into the prepared baking vessel(s).

Second Rise: Leave the dough uncovered or loosely covered on the counter for 20 to 30 minutes or until it has crowned just above the rim of the bowl.

Preheat: Place a rack in the middle of the oven and preheat the oven and your baking vessel (if using a Dutch Oven or lidded pot) to 425°F (220°C).

Bake (High Temp): Score the top of the loaf with a sharp knife or razor blade (optional). Then transfer the vessel(s) to the oven. Bake at 425°F (220°C) for 15 minutes.

Bake (Low Temp): Reduce the oven temperature to 375°F (190°C). Now, continue baking for 20-25 minutes more or until the crust is deep golden brown and the internal temperature is 200°F and 210°F, which is the same as 93°C to 99°C.

Cool: Carefully remove the bread from the oven and immediately turn it out onto a wire rack to cool completely before slicing (at least 30 minutes).