Heat oven to 350 degrees F. Cook the jumbo pasta shells according to package directions. Drain, rinse in cold water, and set aside.
In a large skillet over medium-high heat, add the olive oil. Once the oil is shimmering, add in the garlic and stir for 30 seconds or until fragrant. Add in the ground beef, Italian sausage, and Italian seasoning. Mix and break up the meat. Cook until browned and then remove from the heat and set aside.
In a 9 x 13 baking dish, spread 1 cup of the pasta sauce. Set aside.
In a large bowl, mix cream cheese spread, 1 and 1/2 cups of the Italian cheese, the Parmesan cheese, egg and cooked beef/sausage mixture. Spoon a heaping tablespoon of the mixture into each shell.
Place the stuffed shells over sauce in prepared pan and then pour the remaining sauce over top, covering the shells completely. Cover the pan with foil.
Bake for 35-40 minutes. Sprinkle with the remaining 1/2 cup Italian cheese and cook for 10 more minutes.
Remove and top with fresh parsley and basil if desired.