Put a 6-Quart pot half full of water on the stove and then turn the heat to medium-high to boil the water.
In a large bowl, add the 2-pounds ground beef and 1-pound ground pork sausage.
Add 1 egg to the meat in the bowl.
Measure and add 1 cup breadcrumbs and then add it to the bowl.
Then measure 1 teaspoon each oregano and Italian seasoning and add them to the bowl.
Mix all of the ingredients with your hands, you won't want to get messy, but this is the easiest way to blend it completely.
Then, open the fresh mozzarella package and slice it in half lengthwise, as most fresh mozzarella tubes are precut.
Spray a 9 X 13-inch baking dish with non-stick spray and set it aside.
Preheat the oven to 375 degrees Fahrenheit.
With cleaned hands, grab a handful of meat mixture and flatten in your hand to then make the base for the mozzarella.
Pick up a piece of mozzarella and place in the center of the meat, then fold up the edges and close the meat around the cheese completely, placing each mozzarella stuffed meatball in the prepared baking dish.
When the water is boiling, cook the pasta according to the package directions.
When all of the meatballs are rolled and in the baking dish, bake for 10-15 minutes or until just browned.
Remove the baking dish from the oven, and then one-by-one place the meatballs into a large saucepan on the stove.
Open the jar of spaghetti sauce and then pour onto the meatballs and heat the sauce.
Carefully, with a mug or heat-safe cup, scoop out a cup-full of pasta water and add it to the now empty spaghetti jar, swirl it around carefully and then pour out into the saucepan.
Then cover and reduce heat to medium-low and simmer for 10-15 more minutes.
Once the pasta is cooked, pour into a colander in the sink to drain the water.
Finally, serve the meatballs and sauce over pasta!