1. Prepare the Dough in the Evening: In a large mixing bowl, combine the active sourdough starter, warm water, granulated sugar (or honey), and salt. Stir well until the starter is mostly dissolved. Gradually add the flour, mixing with a wooden spoon or your hands until a shaggy dough forms and no dry streaks of flour remain.

2. Initial Knead and Rest: Turn the dough out onto a lightly floured surface. Knead for about 5-7 minutes until the dough starts to come together and feels a bit smoother. It doesn’t need to be perfectly smooth at this stage. Lightly grease your mixing bowl with olive oil, place the dough back in, turn it once to coat, and cover the bowl tightly with plastic wrap or a damp kitchen towel.

3. Overnight Bulk Fermentation: Let the dough rest at cool room temperature (around 68-72 F) for 8-12 hours, or until it has visibly increased in size (usually doubled) and looks bubbly. If your kitchen is warmer, it might be ready sooner; if cooler, it might take longer. This is the “overnight” part!

4. Shape the Loaf in the Morning: Gently turn the risen dough out onto a lightly floured surface. Gently deflate it and shape it into a rectangular loaf that will fit snugly into your loaf pan. You can do this by gently patting it into a rectangle, then folding the longer sides into the middle, and then rolling it up tightly from one short end to the other. Pinch the seam closed.

5. Second Proof (Final Rise): Lightly grease a 9×5-inch loaf pan with olive oil. Place the shaped dough seam-side down into the prepared pan. Cover the pan loosely with plastic wrap or a clean kitchen towel. Let it rise in a warm spot for another 2-4 hours, or until the dough has risen about 1 inch above the rim of the pan and looks puffy. You can gently poke it with a floured finger; if the indentation springs back slowly, it’s ready.

6. Preheat Oven and Bake: About 30 minutes before baking, preheat your oven to 400 F (200 C). Once preheated, place the loaf pan in the center of the oven. Bake for 35-45 minutes, or until the crust is deeply golden brown and the internal temperature reaches 200-210 F (93-99 C) when checked with an instant-read thermometer.

7. Cool Completely: Once baked, immediately remove the bread from the loaf pan and place it on a wire rack to cool completely. This is a crucial step! Resist the urge to slice into it while hot, as it will be gummy and dense. Allow it to cool for at least 1-2 hours for the best texture and flavor.