Wake up the yeast. In a large bowl, stir together the warm water, sugar, and yeast. Let it sit 5 to 10 minutes until it looks foamy on top. If nothing happens, the yeast may be old. Try again with a fresh packet.
Make the dough. Add 2 tablespoons olive oil and the salt. Stir in 2 cups of the flour until it forms a shaggy mass. Add the remaining cup of flour a bit at a time until the dough is soft and just slightly sticky. You might not need every last tablespoon.
Knead. Turn the dough onto a lightly floured surface and knead 5 to 7 minutes, until smooth and elastic. If using a stand mixer, a dough hook will do the job in about 4 to 5 minutes on medium-low.
First rise. Lightly oil a clean bowl, place the dough inside, and cover. Let it rise in a warm spot for 45 to 60 minutes, until doubled. It should feel airy, like a small pillow.
Prep the skillet and topping. Coat a 10 to 12 inch cast-iron skillet with 1 tablespoon olive oil. In a small bowl, mix the minced garlic, chopped rosemary, and 1 tablespoon olive oil (or melted butter). It’ll smell great already.
Shape. Gently deflate the dough and pat or stretch it into a round that fits the skillet. Place it in, then use your fingertips to dimple the top. Spoon the garlic-rosemary mixture over the surface, letting it settle into the dimples. Sprinkle with a pinch of flaky salt if you like.
Second rise. Loosely cover and let it rest 20 to 30 minutes, until puffy. During this time, preheat the oven to 425°F (220°C).
Bake. Bake 22 to 28 minutes, until the top is deep golden and the center reaches about 200 to 205°F if you check with a thermometer. If it’s browning too fast, loosely tent with foil for the last few minutes.
Finish and cool. Brush the hot bread with a little olive oil or melted butter for a soft sheen. Let it cool 10 to 15 minutes before slicing. It’s tempting to cut right in... but a short rest keeps the crumb tender.
Serve. Tear into wedges and pair with soup, a simple salad, or just olive oil and a pinch of salt. The edges will be crisp, the middle soft, and the garlic-rosemary bits will pop through each bite.