Preheat your oven to 375°F (190°C). Grease a muffin tin with olive oil or line it with muffin liners.
In a large mixing bowl, combine the flour, baking powder, salt, garlic powder, and chopped rosemary. Mix well.
In a separate bowl, whisk together the warm water and 1/4 cup of olive oil.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix; a few lumps are okay.
Divide the batter evenly among the muffin cups, filling each about 2/3 full.
Drizzle a little olive oil on top of each muffin and sprinkle with coarse sea salt and a few rosemary leaves.
Bake for 20-25 minutes, or until the muffins are golden brown and a toothpick inserted into the center comes out clean.
Allow the muffins to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.