In a large bowl, whisk together 3 ½ cups flour, yeast, sugar and salt.
Add in the water and ¼ cup olive oil. Using a spatula, fold until mostly combined. Sprinkle a little more flour if needed to not be sticky and form a ball.
Once ball is formed, grease the same bowl mixed in and place the dough ball back into the bowl.
Cover with a towel or plastic wrap and let sit for 60-90 minutes in a warm, draft free place until doubled.
When ready, add 2 tablespoons olive oil to to a 10x15 baking tray (like a jelly roll pan). Spread and stretch the dough to fill the tray.
Dampen a towel and cover the dough on the tray. Let it sit until doubled in size, approximately 25-45 minutes.
Once doubled, add another 2 tablespoons oil over the top.
Using your finger tips, press down into the dough to make dimples all over the dough (literally push down to make dents into the dough that touch the bottom of the pan).
Sprinkle rosemary and salt across the top.
Bake at 400° for 20 - 25 minutes or until the bread is golden brown on top.