Wash the zucchini well, then slice each one in half lengthwise. Use a spoon or a melon baller to remove the flesh from the center of the zucchini halves, leaving a 1/4 inch rim around each. Place the scooped out zucchini halves in a 9x13" casserole dish or on a large baking sheet. Roughly chop the scooped out zucchini flesh into small pieces and set aside.

Add the olive oil and Italian sausage to a large skillet and sauté over medium heat. Break the sausage up into small pieces as you sauté and cook until the sausage is thoroughly browned (about 5 minutes). Drain off the excess fat.

Add the minced garlic and chopped zucchini to the skillet and continue to sauté until the zucchini pieces are soft (about 5 minutes more). Remove the skillet from the heat.

Begin to preheat the oven to 375ºF. Transfer the sautéed sausage and zucchini to a large bowl. Add the bread crumbs, 1/2 cup of the shredded cheese, and 1/4 cup of the pasta sauce. Stir until everything is evenly combined. Taste and add a pinch of salt and pepper if needed.

Stuff the scooped out zucchini halves with the sausage mixture. Pour the remaining pasta sauce over the zucchini, leaving some of the stuffing exposed so it can brown and crisp up. It's okay if you don't use all the sauce.

Bake the zucchini in the preheated oven for 30-35 minutes, or until the stuffing is brown and crispy and the zucchini are tender. Add the remaining shredded cheese and continue to bake for 2-3 minutes, or until the cheese is melted. Serve hot.