Line the inside of a slow cooker with foil and spray the foil with non-stick cooking spray. Set aside.
To a large mixing bowl, add the ground beef, bread crumbs, milk, onion, eggs, parsley, Worcestershire, salt, Italian seasoning, garlic powder, and pepper. Use your hand to mix everything together until well combined. (Do not overmix.)
Shape the meatloaf mixture into a large oval shape on top of the foil in the crock.
In a small bowl, whisk together the ketchup and brown sugar. Brush half of the glaze over the meatloaf.
Cover and cook on LOW for 4-5 hours or until the meatloaf is cooked through and has an internal temperature of 160 degrees F.
Brush the remaining glaze onto the meatloaf and sprinkle with chopped parsley for garnish. Cut into slices and serve warm with your favorite sides.
Notes
Nutritional information is based on 1 meatloaf cut into 8 slices.