Preheat oven to 375 F.
Place zucchini noodles (5 cups) in a colander and toss in salt (1 teaspoon). Allow them to sit for 15 minutes. After 15 minutes, place them in a clean kitchen towel and gently ring out any additional liquid.
Meanwhile, cook the Italian sausage (1 Lb) until brown, breaking up with the tip of a wooden spoon as it cooks. Allow cooked sausage to drain excess grease on a paper towel-lined plate.
Add zucchini noodles, sausage, chopped red onions (1 cup), bell peppers (1 chopped), black olives (1/2 cup), and low carb pizza sauce (16 ounces) to a 9x13 casserole dish and toss to combine.
Sprinkle the top with mozzarella cheese (2 cups) and pepperonis (15 slices).
Bake in the oven for 20 minutes, or until the top become golden brown.
Allow casserole to cool slightly before slicing, and enjoy!