foccacia recipe

2 1/4 teaspoons active dry yeast (one packet) - 1 teaspoon sugar - 1 3/4 cups warm water (110°F or 45°C) - 5 cups all-purpose flour - 1/4 cup olive oil, plus more for greasing and drizzling - 1 tablespoon salt - 2 teaspoons dried rosemary (or fresh, if you prefer) - Optional: flaky sea salt, additional herbs, or toppings (such as cherry tomatoes, olives, or caramelized onions)