Instructions:

1. Activate the yeast: In a bowl, combine warm water, yeast, and sugar. Let sit for 10 minutes until frothy.
2. Mix the dough: In a large bowl, combine flour and salt. Gradually add the yeast mixture and olive oil. Knead until smooth, about 8-10 minutes.
3. Let the dough rise: Cover the dough with a damp cloth and let it rise for 1-2 hours, or until doubled in size.
4. Prepare the focaccia: Preheat the oven to 400°F (200°C). Transfer the dough to a greased baking pan, pressing it out evenly. Dimple the surface with your fingers and drizzle with olive oil. Sprinkle with rosemary and flaky salt.
5. Bake: Bake for 20-25 minutes, or until golden brown.
6. Serve: Let cool slightly before slicing and serving warm.