In a large bowl, add the flour, salt, yeast, oil and warm water. Using a dough whisk or your hands, mix until everything is well combined and a wet, sticky dough forms. Cover and let the dough rest at room temp for 15 minutes.
480 grams all purpose flour, 2 ½ tsp salt, 2 tsp active dry yeast, 408 grams warm water, 105-110°F, 2 Tbsp olive oil
After 15 minutes, stretch and fold the dough. With wet hands, grab one edge of the dough, gently pull it upward, and fold it toward the center. Turn the bowl slightly and repeat with another section of dough. Continue this process until you have stretched and folded the dough 4–5 times.
Cover the dough and let rest another 15 minutes. Repeat the stretch and fold process. Rest the dough for another 15 minutes, then repeat the stretch-and-fold process one final time, for a total of 3 rounds of stretching and folding.
After the third and final stretch and fold, cover the dough and let rise at room temp, or in a warm, draft-free spot, for 45 minutes.
Drizzle a 9x13 inch baking pan with 2 Tbsp of olive oil. Transfer the dough to the baking pan and, using lightly oiled or wet hands, gently stretch the dough towards the edges of the pan. (If the dough does not reach all the way to the edges yet, that’s okay! It will spread as it rises.)
3 Tbsp olive oil, for baking pan and topping
Cover the baking pan and allow the dough to rise for another 2 hours, until the dough has doubled in size and looks fluffy and bubbly. (Do NOT rush this step! The dough needs enough time to rise properly for the best texture and flavor.)
About 20–30 minutes before the dough is finished rising, preheat the oven to 450°F. This ensures the oven is fully heated when the focaccia is ready to bake.
Uncover the dough and drizzle with 1-2 Tbsp of olive oil. Wet your hands, then gently press your fingertips straight down into the dough to create deep dimples. Continue until the entire surface of the dough is covered with dimples. Top with fresh rosemary and flaky salt.
4 Tbsp rosemary, fresh or dried optional, Flakey salt, optional, 3 Tbsp olive oil, for baking pan and topping
Bake at 450°F for 20-25 minutes, until the focaccia is deep golden brown and crisp around the edges.
Remove the focaccia from the oven and let it cool in the pan for 5-10 minutes. Then, carefully transfer it to a wire cooling rack and let it cool slightly before slicing and serving.