5 tablespoons warm water (110 degrees F/45 degrees C)
or more as needed
2 ½ teaspoons active dry yeast
1 teaspoon white sugar
2 cups all-purpose flour
¼ teaspoon salt
or more to taste
2 tablespoons olive oil
3 sprigs fresh rosemary
Combine 5 tablespoons warm water, yeast, and sugar in a large bowl. Let stand until creamy, about 10 minutes.
Add flour and 1/4 teaspoon salt to the yeast mixture; stir well to combine. Stir in 1 tablespoon additional water at a time, if necessary, until all flour is absorbed and mixture has pulled together into a dough. Turn out onto a lightly floured surface and knead until springy, 4 to 6 minutes.
Lightly oil a large bowl. Place dough in the bowl and turn to coat with oil. Cover with a damp cloth and let rise in a warm place until doubled in volume, about 30 minutes.
Preheat the oven to 465 degrees F (240 degrees C). Lightly grease a baking sheet.
Deflate dough and turn out onto a lightly floured surface. Knead briefly, then pat or roll dough into a sheet and transfer to the prepared baking sheet. Brush with remaining oil and make dimples across the surface with your fingertips. Sprinkle with rosemary leave and extra salt to taste.
Bake in the preheated oven to desired crispness, about 10 minutes for light and fluffy or 20 minutes for crunchier and darker on the outside.