Combine the warm water and yeast in the bowl of your stand mixer. Let it sit for about 5 minutes until slightly foamy.

Add the remaining water, bread flour, kosher salt, and olive oil.

Mix on low until combined, then increase to medium speed and knead for about 5 minutes until the dough becomes smooth and elastic.

Don’t worry—it will still be extremely sticky.

Transfer the dough to a generously oiled bowl.

Cover and let it rise until doubled in size, about 1½ to 2 hours depending on room temperature.

Using well-oiled hands, gently stretch and fold the dough over itself several times.

This strengthens the gluten without additional kneading.

Coat a half-sheet pan generously with olive oil.

Transfer the dough to the pan and gently stretch it toward the corners.

If it springs back, let it rest for 15–20 minutes before stretching again.

Cover the pan loosely.

Let the dough rise until puffy and bubbly, about 45 minutes to 1 hour.

Drizzle the remaining olive oil over the dough.

Using your fingertips, press deep dimples across the surface.

Sprinkle generously with rosemary and flaky sea salt.

Bake in a 450°F (230°C) oven for 25–30 minutes until deeply golden brown with crisp edges.

Cool for at least 15 minutes before slicing.