In the bowl of a stand mixer fitted with the dough hook attachment, combine water, yeas and sugar. Gently stir, then set aside and allow the yeast to bloom for 7 minutes.
Add the flour and salt and mix on low until all the flour has been incorporated. You may need to stop and scrape the bowl down with a rubber spatula. Then, turn the speed to medium and mix the dough for 5 minutes.
Add 2 tablespoons of olive oil to the bottom of a large mixing bowl. Swirl the oil around to coat the sides. Then, scoop the dough into the bowl. Use a rubber spatula to help get all the dough into the bowl.
Then, use a spoon to take oil that has pooled at the sides of the bowl and drizzle it on top of the dough. Cover and allow the dough to rise until it doubles in size, about 2 hours.
Prepare a 9 by 13 inch baking pan by rubbing it liberally with non-dairy butter. Then, add two tablespoons of oil into the pan and tilt it to coat the bottom. Scoop the dough into the prepared baking pan and use your hands to spread it out. Cover and allow the dough to proof for 30 minutes.
Preheat oven to 450* F.
After 30 minutes, uncover the dough and drizzle the top with two tablespoons of olive oil. Use your fingers to dimple the dough evenly. Then, top with flakey sea salt if using.
Bake the focaccia on the middle rack of a 450* F oven for 25-30 minutes or until the focaccia is golden brown all the way across the top. Serve warm.