Cook the onions on medium-low heat in oil until browned. When they reach a caramelized stage (caramel in color), sprinkle on the sugar and stir. Set aside to cool.
Stir the yeast and water together, allowing the yeast to bloom for a few minutes. Meanwhile, mix the flour, salt, and onion powder in a large bowl.
Mix the two together just until there are no dry spots left in the flour and it’s well combined; no need to mix it forever. Add in ¾ of the caramelized onions.
Cover with a wet tea towel, and let sit for 2-10 hours. If you’re going for just 2 hours, make sure it’s in a warm place.
Line a baking pan with parchment paper and pour 3 tablespoons of olive oil onto it.
Gently dump the dough onto the pan, flip it to coat in oil, and then let it rest 20 minutes.
Preheat the oven to 450°F while it rests.
Oil your fingers from some excess oil on the pan, and press the dough out to fit the pan.
Dimple the dough all over with your fingers, then spread the remaining caramelized onions on top and press them in.
Bake for 20-25 minutes, rotating the pan halfway through to bake evenly.
Serve immediately.