Step 1

Line the insert of a 6-quart slow cooker with aluminum foil. Coat the foil with cooking spray.

Step 2

In a large bowl, combine the ground sirloin, eggs, zucchini, Parmesan cheese, parsley, garlic, oregano, onion powder, salt, and pepper. The mixture will be very loose; this is expected.

Step 3

Carefully transfer the mixture into the slow cooker and form into an oblong-shaped loaf, setting it on top of the aluminum foil.

Step 4

Cover and cook for 6 hours on low or for 3 hours on high. When you have 15 minutes left, turn off the heat and unplug the slow cooker. Remove the cover and spread the marinara sauce over the top of the meatloaf. Sprinkle the cheese on top of the sauce and replace the cover. Allow the meatloaf to sit for 5 to 10 minutes or until the cheese has melted.

Step 5

Lift the foil to remove the meatloaf. Transfer the loaf to a serving platter and garnish with fresh parsley. Slice and serve.