Prepare the yeast mixture. Combine the yeast, sugar, and the warm water in a large mixer. Be careful to use WARM water, not hot. Mix and let sit for about 15 minutes to get the yeast working. It should foam up.
Add the salt and olive oil, and stir with a spatula. Attach dough hook to mixer and then add three cups of the flour. Start the mixer, and let it run until flour is fully absorbed.
Gradually add remaining cup (or more). You want the bread dough to be slightly sticky but not too much. Be sure to leave the mixer on for several minutes after you get the right consistency.
Grease a large bowl with olive oil. Add dough to the bowl, making sure you smooth it into a ball. Cover the dough with a clean dish towel and set it in a warm corner of your kitchen. Let the dough rise until doubled in size.
Prepare a half baking sheet (mine is 10 x 15 but you could use a 9 x 13 or a couple of round pans) with a tablespoon of olive oil. Place the dough round on top and pour another tablespoon on top. Then use your hands to stretch it out over the pan.
After the dough is stretched to the edges, use your fingertips to make little imprints all over the dough.
Cover the dough with a dish towel, and let the dough rice again until doubled in size, about an hour.
Drizzle the dough with the remaining tablespoon of olive oil, so it pools into the little imprints, and then sprinkle with the fresh rosemary and kosher salt. Let rise again until doubled in size, about 45 minutes.
Bake at 400 degrees for approximately 20 - 23 minutes, until golden brown on top. Transfer to cooling racks.
Cut and serve!