Combine the warm water, yeast, and sugar in a measuring cup and let stand at room temperature for 15 minutes, until frothy. In the bowl of a mixer fitted with a dough hook, stir together the yeast mixture, flour, salt, and 1/2 cup olive oil until a dough forms. Allow the mixer to knead the dough for 6 minutes on medium speed until smooth, adding a sprinkling of extra flour if necessary.
Transfer the dough to an oiled bowl, cover with a damp kitchen towel, and allow to rise until doubled in size, about 1 hour. Add the remaining 1/2 cup olive oil to a rimmed sheet pan. Spread out the dough on the pan until it completely covers the surface of it. Make sure all of the dough is coated in oil, and spread the dough out with your fingers, making holes in the dough as you go (the dough will rise again, and fill in those holes).
Allow the dough to rise again, for an hour. Preheat the oven to 425 degrees F. Bake for 25-30 minutes, until golden brown. Allow to cool.
Slice up the focaccia and enjoy with all your toppings!