Preheat oven to 400°F. Line a rimmed baking sheet with aluminum foil and coat with cooking spray.
In a large bowl, combine beef, eggs, cheese, bread crumbs, parsley, salt and pepper until well-combined (do not over mix). Divide beef mixture into 6 even portions and form into mini loaves; place on prepared baking sheet. Spoon 3 tablespoons marinara sauce over each loaf and bake until cooked through, about 35 to 40 minutes; allow to rest for 10 minutes before serving.
Meanwhile, bring a large pot of salted water to a boil. Cook pasta according to package directions. Once pasta is cooked, reserve 1/4 cup of pasta cooking liquid and then drain pasta.
While pasta and meatloaves cook, heat oil in a large nonstick skillet over medium-low heat. Add garlic; cook, stirring occasionally, until lightly browned, about 2 to 3 minutes. Once garlic begins to brown, add zucchini; increase heat to medium-high and cook zucchini, stirring occasionally, until lightly browned and soft, about 6 to 7 minutes. Season to taste with salt and then add pasta and reserved cooking liquid to pan; stir to combine and cook for 1 minute to heat through.
Heat remaining marinara sauce; spoon 1 tablespoon sauce over each meatloaf before serving. Yields 1 meatloaf, about 1 cup pasta-zucchini mixture and 1/2 teaspoon cheese garnish per serving.
If zucchini starts to stick to pan, remove from heat and coat with cooking spray; finish cooking as directed above.