In a mixing bowl, combine beef, sausage, raisins, garlic, 1/2 cup Parmesan cheese, parsley, egg, salt and pepper. Form small balls from the meat mixture, no larger than golf balls, and place in the refrigerator for 10 to 15 minutes.
Heat a skillet over medium-high heat and add oil. Cook the meatballs until browned on all sides. Remove from pan.
Add the onion and saute for 5 to 7 minutes, then add the red pepper flakes. Crush the tomatoes with your hands as you add them to the pan. Stir to combine. Bring to a boil and then reduce to a simmer. Add the meatballs back to the pan and simmer for 15 minutes.
To cook zucchini noodles: First use a vegetable peeler to shave the zucchini into long noodle-like strands, starting at one end with the peeler and shaving all the way down to the opposite end.
Heat a skillet over medium heat and add the zucchini strands. Cook for 2 to 3 minutes.
Plate the zucchini noodles and top with meatballs and sauce.