In a small bowl, combine the warm water, sugar, and yeast. Stir lightly.
In a large bowl, whisk together the gluten-free flour blend, baking powder, and 1/2 teaspoon salt. Add the yeast mixture and 2 tablespoons olive oil. Stir until the ingredients form a sticky batter.
Drizzle the remaining 1 tablespoon of olive oil over the dough. Sprinkle with chopped fresh rosemary, the rest of the salt, and minced garlic if using.