In a large bowl, whisk together flour, salt, and baking powder. Set aside.
In a smaller bowl combine warm water with year, sugar, and olive oil. Stir to combine, then let it bloom by setting it aside to rest for 3-5 minutes. (It should start to look foamy on top)
Pour the water/yeast mixture over the dry ingredients and stir to combine. Note that your dough should look more like a batter. Kneading is not required here.
Cover the bowl with plastic wrap or a clean dish towel and set it to rise in a warm place for about 40min.
During the last few minutes of the rise time, preheat the oven to 190°C (375° F)
Line a baking sheet (standard cookie sheet pan, you will form the focaccia bread with your hands) with parchment paper and drizzle with a little bit of olive oil. The olive oil gives the bottom crust great crunch and flavor.
Pour the batter out onto the prepared baking sheet and gently press out using your fingers or the back of a spatula into an oval or rectangular shape (about 3/4 of an inch thick)
Use your finger to poke several holes in the dough all the way to the bottom of the pan. Press the olives into the dough. Brush with olive oil and sprinkle with fresh rosmary, coarse salt and grated parmesan cheese (if using)
Bake at 190°C (375° F) for 25-30 minutes, or until golden brown. Remove from oven and let cool at least 10-12 minutes before slicing and eating.
The focaccia will keep at room temperature for up to 2 days or in the freezer for up to 1 month. Read more about storing tips, in the article above