Preheat the oven to 350°F (175°C). Spray a 9x13-inch baking dish with nonstick cooking spray and set aside.
Boil the lasagna noodles according to package directions until al dente, drain in a colander, and set aside.
In a large skillet over medium heat, cook the ground beef and Italian sausage until browned. Drain off excess fat.
Add the Stone House Seasoning, dried basil, dried oregano, pasta sauce, and tomato paste to the skillet. Stir to combine and simmer 5–10 minutes until slightly thickened; set aside.
In a large bowl, lightly beat the egg. Add the softened cream cheese, Greek yogurt, 2 cups shredded mozzarella, 1/4 cup shredded Parmesan, and chopped parsley (if using); stir until smooth and well combined.
Spread 1 cup of the meat sauce in the bottom of the prepared baking dish. Arrange a layer of lasagna noodles over the sauce.
Spread one-third of the cheese mixture over the noodles, then top with 1 cup of meat sauce. Repeat layering two more times (noodles, one-third cheese mixture, 1 cup sauce).
Top with a final layer of lasagna noodles and spread the remaining meat sauce over the top.
Cover the dish loosely with aluminum foil and bake in the preheated oven for 40 minutes.
Remove the foil and sprinkle the remaining 2 cups shredded mozzarella and 1/4 cup Parmesan evenly over the lasagna. Bake uncovered until the cheese is browned and bubbly, about 15 minutes.
Let the lasagna rest for 10 minutes before cutting and serving.
