Cook the Pasta: Bring a large pot of salted water to a rolling boil. Add the whole wheat penne pasta and cook until al dente, about 1-2 minutes short of the package instructions. Drain the pasta in a colander, reserving ½ cup of the starchy pasta water.

Brown the Meat: In a large skillet over medium-high heat, add the lean ground beef along with the diced onion and minced garlic. Cook for about 8-10 minutes until the beef is well-browned. Drain any excess grease and season with Italian seasoning, salt, and pepper.

Mix the Creamy Base: In a mixing bowl, combine the cottage cheese and plain Greek yogurt. Blend until the mixture is smooth and creamy.

Preheat the Oven: Preheat your oven to 375°F (190°C).

Layer the Ingredients: In your prepared baking dish, layer the cooked pasta at the bottom, followed by the beef mixture and marinara sauce. Stir to distribute evenly.

Add the Creamy Mixture and Toppings: Spread the creamy cottage cheese mixture evenly over the pasta layer, then top with shredded mozzarella and grated Parmesan cheese.

Bake Until Golden: Place the dish in the oven and bake for 20-25 minutes until the cheese is bubbling and golden brown.

Rest and Garnish: Remove from oven and let it rest for 5-10 minutes. Garnish with fresh parsley before serving.