Pre-heat oven to 350° (180° celsius), lightly grease with olive oil a small to medium baking pan. I used an 8x6 inch (20x15 cm) baking dish and I made 4 layers.
Shred the cheese and mix the parmesan cheese with the chopped parsley. Set aside.
Slice the zucchini lengthwise into strips that are not too thick. Place them in a large bowl and toss them with the salt. Let sit for 20 minutes then drain but do not rinse. Then paper towel dry the zucchini to remove as much excess moisture as possible. These steps are important because the salt and towel drying will draw out the excess liquid in the zucchini. That’s what keeps it from turning mushy in the oven.
Place the flour in a shallow dish and dredge each zucchini slice in it.
First do an even layer of zucchini slices in the prepared baking dish. If using the pancetta then top some on the zucchini, sprinkle 1/3 or 1/4 of the mozzarella (depending on how many layers you want to make) on top then finish with 1/3-1/4 of the grated parmesan, add another layer of each repeating this process until you’ve used up the ingredients.
Bake the casserole for about 25 minutes. Let it stand at room temperature for about five minutes before slicing and serving. Enjoy!