Preheat oven to 450 degrees Fahrenheit. In a large mixing bowl, add 2½ cups grated zucchini, squeezed dry and liquid removed , 2 lightly beaten large eggs, ¼ cup all-purpose flour, and 1 ½ teaspoons salt and mix. Add ¼ cup grated parmesan cheese and ½ cup shredded mozzarella cheese and mix until incorporated.
On a 12-inch pizza dish, spread zucchini crust into a 10-inch circle. Bake for 13-16 minutes or until golden brown and set.
Remove the crust from the oven and reduce oven temperature to 400 degrees Fahrenheit. Add ¼ cup pizza sauce, 1 cup shredded mozzarella cheese, ½ cup shredded cheddar cheese, ¼ cup pepperoni, ¼ cup sliced olivesolives, and ½ cup sliced mushrooms to the zucchini crust and sprinkle with 1 teaspoon dried oregano.
Put back into the oven and bake for 10-13 minutes more or until cheese is melted and bubbly. Top with freshly fresh chopped basil for garnish if desired.