Sourdough Focaccia: Crispy and Pillowy

Instructions:

1. Combine the active sourdough starter and lukewarm water in a large bowl, whisking until the starter is fully dissolved.
2. Stir in the bread flour and fine sea salt until a shaggy, sticky mass forms.
3. Perform a series of stretch and folds every 30 minutes for the first 2 hours to develop gluten structure.
4. Cover the bowl with a damp cloth or plastic wrap and ferment at room temperature for 4–6 hours, or in the refrigerator for 12–18 hours for maximum flavor.
5. Pour 3 tablespoons of olive oil into a 9x13 inch metal baking pan.
6. Transfer the dough to the pan, stretch it to the corners, and use your fingers to create deep dimples across the surface.
7. Drizzle with the remaining olive oil and top with flaky sea salt and fresh rosemary needles.
8. Bake for 20 minutes until the crust is mahogany-colored and crisp.