Step 1

Preheat the oven to 400°F. Spray a large 13x9-inch baking dish with non-stick cooking spray. Set aside.

Step 2

Prepare the zucchini: Slice each zucchini in half lengthwise. Use a spoon to carefully scoop out the fleshy seed-filled center from each zucchini half. Leave about 1/4-inch on all sides.

Step 3

Drizzle the zucchini boats with approximately 1 tablespoon olive oil and transfer to the prepared baking pan. Sprinkle with salt and pepper. Bake in the preheated oven for 15-20 minutes.

Step 4

As the zucchini bakes heat the remaining tablespoon of olive oil in a large skillet set over medium heat. Add the onion and cook until softened, about 5 minutes. Add the minced garlic and continue to cook for 1 minute, stirring often.

Step 5

Add the ground sausage, breaking it apart into smaller pieces as it cooks. When the sausage is nearly cooked, season it with Italian seasoning, dried basil, salt, and black pepper. Add the capers and marinara sauce. Mix well to combine and continue to cook for an additional 2-3 minutes, stirring as needed.

Step 6

Remove from heat and stir in the parmesan cheese.

Step 7

Divide the prepared sausage mixture among the zucchini boats and top each zucchini boat with the shredded mozzarella cheese.

Step 8

Bake in the oven until the zucchini is tender and the cheese is melted - about 15 minutes. Sprinkle with red pepper flakes, if desired.