Arrange the top oven rack 6 inches from the broiler. Turn the broiler on high.
Grease a rimmed baking sheet with avocado spray and set aside.
In a large bowl, combine the beef, mashed cauliflower, onion, basil, ½ cup minced parsley, minced garlic, Magic Mushroom Powder or Diamond Crystal kosher salt, oregano, and black pepper.
Use your hands to gently combine the ingredients until well-combined, but don’t overwork the meat.
Microwave a small spoonful of the meat for 30 seconds or fry it in a small frying pan until fully cooked to check for seasoning. Add more Magic Mushroom Powder and black pepper if needed.
Use your hands to roll out 12 evenly sized meatballs that are about 3-inches in diameter. Arrange the meatballs on the greased rimmed baking sheet, making sure they are evenly spaced.
Broil the meatballs for 8 to 10 minutes or until browned on top.
While the meatballs are broiling, bring the marinara to a boil in a 12-inch skillet over high heat. Turn the heat down to maintain a simmer.
When the meatballs are ready, transfer them to the simmering sauce. Partially cover the pan and simmer for about 10 minutes or until the meatballs are fully cooked.
Top with reserved ¼ cup minced Italian parsley. Serve with zoodles, gluten-free pasta, or cauliflower mash.