1. Brush a large bowl with oil; set aside. Stir together water, sugar, and yeast in a medium bowl until yeast has dissolved. Let stand until foamy, about 5 minutes.

2. Stir together flour, rosemary, and salt in a medium bowl. Add oil to yeast mixture; stir into flour mixture until a dough forms. Turn out dough onto a lightly floured surface; knead with floured hands until smooth, 5 to 6 minutes. Transfer to oiled bowl; turn to coat. Cover with plastic wrap; let rise in a warm, draft-free place until doubled in bulk, about 45 minutes.

3. Remove plastic wrap; punch down dough. Shape into a round. Cover with plastic wrap; let rise again until doubled in bulk, about 30 minutes.