In a bowl, mix warm water, yeast, and sugar. Let sit for 5–10 mins until frothy.
Add flour, 1 tsp salt, and ¼ cup olive oil to the yeast mixture. Stir until combined (dough will be sticky).
Cover with a towel and let rise in a warm place for 1–2 hours, or until doubled in size.
Pour 2 tbsp olive oil into a 9x13-inch pan. Transfer dough to the pan, stretching it to fit.
Use your fingers to press dimples into the dough. Drizzle with remaining oil, rosemary, and sea salt.
Let rise for 20–30 mins while preheating the oven to 425°F (220°C).
Bake for 20–25 mins until golden. Cool slightly before slicing.
