This was more of a method than an actual recipe until my young friend, Mason, who was here and helped to make these asked if I'd write down how to do it so he could take the recipe home with him and make it for his mom and grandparents. So, best as I could, I typed this out for him. And, thought I'd post it here, in case he loses it or I forget what we did.
Will come back and post photo(s) when we do it again.
Preheat oven to 400º F. Brush a 9” x 9” baking dish with olive oil and set aside.
Pulse the bread in a food processor to make coarse crumbs. Transfer to a small bowl, add the milk and set aside to soak.
Lightly beat the egg in a mixing bowl, then add the beef, parsley, parmesan, garlic, salt and red pepper flakes, if using; using your hands, mix lightly. Add the bread-milk mixture and stir/toss with wooden spoon until just combined.
With damp (not wet) hands, shape the meat mixture into 8-10 meat balls. Push a ¾” length piece of string cheese into each meatball, reforming the meat mixture around the cheese.
Arrange the meatballs on the prepared baking dish and bake until browned - 25 to 30 minutes.
Remove the meatballs from the oven and pour off any excess grease. Pour can/jar of prepared sauce over meatballs and dollop spoonfuls of ricotta on top of each meatball. Continue cooking about 5 more minutes, or just until ricotta and sauce is heated through.
Remove from oven and sprinkle on the chopped basil leaves. Serve with your favorite pasta, a green or yellow vegetable and hot garlic toast.
NOTE: Meatballs can be formed a day in advance; just cover and refrigerate until 30 minutes before you’re ready to bake. Allow to come to room temperature before placing in oven, otherwise, your cook time will be off.