In a large mixing bowl, combine the warm water and granulated sugar. Sprinkle the active dry yeast over the water. Let it sit for 5-10 minutes until foamy, indicating the yeast is active.

Add the all-purpose flour, fine sea salt, and 2 tablespoons of olive oil to the yeast mixture. Stir with a wooden spoon or spatula until a shaggy, sticky dough forms and no dry streaks of flour remain. Do not overmix; a few lumps are fine.

Cover the bowl tightly with plastic wrap or a clean kitchen towel. Let the dough rise in a warm place for 1.5 to 2 hours, or until it has doubled in size and looks bubbly.

Generously grease a 9x13 inch baking pan with 2 tablespoons of olive oil, ensuring the bottom and sides are well coated.

Gently scrape the risen dough into the prepared baking pan. With oiled hands, gently spread and stretch the dough to fill the pan, being careful not to deflate it too much. If the dough springs back, let it rest for 5-10 minutes, then continue stretching.

Cover the pan with plastic wrap or a kitchen towel and let it rise again for another 20-30 minutes, or until slightly puffy.

While the dough is on its second rise, preheat your oven to 400°F (200°C).

Remove the cover from the risen dough. Drizzle the top generously with 2-3 tablespoons of extra virgin olive oil. Using your fingertips, gently press dimples all over the surface of the dough, making sure to press down to the bottom of the pan but not through the dough.

Sprinkle evenly with flaky sea salt and any optional toppings like fresh rosemary or sliced garlic.

Bake for 25-30 minutes, or until the focaccia is golden brown on top and cooked through. If it's browning too quickly, you can loosely tent it with foil.

Once baked, immediately transfer the focaccia to a wire rack to cool slightly. Serve warm or at room temperature. Enjoy!