In a large bowl, whisk together the water, granulated sugar, and active dry yeast. Set aside for 5 minutes, or until the yeast has bloomed. 

In another bowl, stir together the flour, ½ cup parmesan cheese, rosemary, garlic, and salt. 

Once the yeast has bloomed, whisk in ¼ cup of olive oil. Then, add the flour mixture and stir until a shaggy dough forms. 

Turn the dough out onto a clean surface and knead until the dough is smooth and elastic-- about 5 minutes. 

Transfer the dough to a lightly oiled bowl and place it in a warm place to rise for two hours, or until it has doubled in size. Make sure to save the remaining olive oil and parmesan for later! 

Once the dough has risen, add the remaining ¼ cup olive oil to a quarter sheet pan. Transfer the dough to the pan and toss it to fully coat the dough with oil. 

Spread the dough until it fully fills the pan. Cover the pan and set it in a warm spot to rise again until it reaches the top of the pan-- about 1 hour. 

Once the dough has risen, preheat your oven to 425F. 

Use your fingers to dimple the dough and create wells all over the focaccia. Then, sprinkle over the remaining parmesan. 

Bake for 20-22 minutes, or until the focaccia is golden brown around the edges. 

Remove from the oven and allow it to sit for 5 minutes before slicing. Serve with a drizzle of olive oil and a sprinkle of flake salt.