In a small pot, over medium heat, warm the milk to 100°F to 105°F.
Place warmed milk in a small bowl; stir the sugar into the milk; sprinkle the yeast over the sugar milk mixture; set aside for 5 to 10 minutes until the mixture is bubbly.
In the bowl of a stand mixer, place the flour, 1 tablespoon olive oil and 1 teaspoon of the salt; mix together briefly using the dough hook; add the yeast/milk mixture and begin to knead, adding the water gradually; the mixture should come together as a soft, stretchy dough, pulling away from the sides of the bowl; add a bit more flour if the mixture is too wet or add a bit more water if the mixture seems dry, crumbly or overly firm.
Knead for 5 to 10 minutes, until dough is smooth, soft and elastic. Oil a bowl with olive oil and place the dough in the bowl; cover with plastic wrap and let the dough rise on the counter until doubled in size; about 1 hour.
While the dough is rising, peel and slice the onion into very thin strips; place in a bowl of cold salt water (using the remaining 1 teaspoon salt and 3/4 cup water) and soak for 30 minutes; drain onions well and dry with paper towels. Once the dough has risen, punch it down and divide dough into two pieces; roll each half into a smooth ball. Pour 3 tablespoons of olive oil into a 12-inch pizza pan or cast-iron skillet; place one ball of dough in the middle of the pan and flatten gently with your fingers; let the dough relax for 10 minutes.
Continue to flatten dough into the pan, flattening it and pushing it toward the sides of the pan, letting it relax in between until dough covers the bottom of the pan; oil the counter and roll the other piece of dough into a 12-inch circle, letting it relax in between until it holds its shape.
Pre-heat the oven to 450°F.
Place the slices of mozzarella cheese over the dough in the pan; sprinkle the provolone over the mozzarella; place the other round of dough over the cheese and seal the edges of the two dough circles together.
Top the pizza with the sliced onions; drizzle a tablespoon of olive oil over the onions; sprinkle with the dried oregano and some Parmesan cheese.
Place the fugazzeta in the pre-heated oven and bake for 20 to 25 minutes, or until the edges are golden brown and crispy; brown the onions under the broiler for the last 3 minutes of cooking, if desired.
Remove from the oven; allow to for 5 to 10 minutes before cutting into slices to serve.
