Slice the zucchini thin and place in a bowl with 1 tsp salt. Toss the zucchini rounds in the salt and allow the zucchini to release it’s water. Set aside for 15 minutes. After 15 minutes, add the zucchini to a clean kitchen towel and ring out the excess water into a bowl. Set the zucchini aside. Reserve the water for later.
Preheat the oven to 425 degrees F.
To a medium size bowl add the flour, cornmeal, spices, eggs, olive oil, zucchini water and about 1 cup of the Parmigiano Reggiano. Mix to combine. The batter should be very thick. Add the zucchini and onions. Mix to combine.
Line an 11 x 9 baking sheet with parchment paper. Brush the parchment paper with olive oil. Pour in the batter and carefully spread it out into a thin layer. Drizzle the top with olive oil and add the remaining Parmigiano Reggiano.
Bake in the oven for 30-35 minutes until the scarpaccia is golden. Let cool before slicing.
