Preheat oven to 375 degrees Fahrenheit. Line a baking sheet with parchment paper.
Scoop out the flesh of the zucchini, leaving a border of approximately 1/3-inch. Set aside zucchini flesh and place zucchini boats on the baking sheet.
Sprinkle inside of zucchini boats with salt.
Optional: Chop zucchini flesh and split between the 4 zucchini boats.
Add pizza sauce evenly to the zucchini boats then top with mozzarella, Italian seasoning, red pepper flakes, olives, red onion, and parmesan.
Bake for 20 minutes until zucchini is tender and cheese is bubbling. Turn on broiler to high and cook 2 minutes till top is golden brown.
Garnish with basil and serve immediately.