Combine ground beef, Italian sausage, onion powder, garlic powder, 1 tbsp chopped basil, parmesan, 3/4 tsp salt, pepper, 1 tbsp olive oil, eggs, breadcrumbs, and whole milk in a large bowl. Mix just until combined.
Heat a large sauté pan over medium-high heat and drizzle in 1 tbsp olive oil.
Form meatballs into 16 even portions and roll each into a ball. Place on a baking sheet until ready to cook.
Cook your meatballs for 3-4 minutes on a side until browned fully. Transfer to a baking sheet lined in tin-foil to rest while you make your sauce.
Turn the heat down to low and add 1 chopped shallot and 6-8 cloves of finely chopped garlic. Sautee for 3-4 minutes until translucent and soft.
Add your crushed tomatoes, remaining basil, 1/4 tsp salt, water, and stir to combine into a sauce.
Turn heat up to medium and cook for 5 minutes until bubbly. Transfer your meatballs back into the sauce and cover.
Cook meatballs for 5 minutes, covered, then turn them and cook for another 10 minutes, covered. Turn off the heat and let meatballs sit until ready to serve.
At this point, if you are making meatball subs, place fresh slices of mozzarella on top and cover until melted.