Stir together yeast and warm water in the bowl of a heavy-duty electric stand mixer; let stand 5 minutes. Get ready for some serious beating!

Add bread flour, 1/4 cup oil, and 1 Tbsp. table salt to yeast mixture. Beat on low speed with a  paddle attachment until properly blended, probably around 10 seconds. Increase the speed to medium and beat for 45 seconds or until the dough is smooth. Add in a Tbsp. rosemary. Replace the paddle attachment with a dough hook, and increase speed to medium-high. Beat that sucker for 4 minutes. Mind your hands, that dough's gonna be sticky.

Turn the dough onto a floured surface, and knead for a minute until smooth and elastic. Place in a greased bowl, turning to coat. Cover the dough with plastic wrap, and let rise in a warm place (80° to 85°), free from drafts, for 1 hour. Its bulk should be doubled when it's ready.

Press the dough into a pre-greased 15- x 10-inch jelly-roll pan, pressing to about 1/4-inch thickness. Cover with a kitchen towel, and let it continue rising in the warm spot for 1 hour.

Preheat your oven to 475°. Press the handle of a wooden spoon into the dough to make indentations at 1-inch intervals and drizzle with 3 Tbsp. oil. Sprinkle with kosher salt and remaining Tbsp. rosemary. Bake 14 to 16 minutes or until top is light brown. Remove from pan to a wire rack, and let it cool 10 minutes.