In a large skillet over medium heat, brown the ground beef until halfway cooked, about 3-4 minutes. Stir in diced onion and minced garlic, cooking until the beef is fully browned and the onion is translucent, roughly 5 more minutes. Add tomato sauce, Italian diced tomatoes, sugar, and dried parsley. Bring to a gentle simmer for 15 minutes, stirring occasionally.

In a large pot of salted water, bring to a boil. Add lasagna noodles and cook until al dente, approximately 8-10 minutes. Drain and rinse under cold water to prevent sticking. Lay noodles out on a large baking sheet.

In a medium bowl, soften cream cheese at room temperature. Stir in Italian seasoning until smooth and creamy. This mixture will be dolloped between layers.

Preheat your oven to 350°F (175°C). In a baking dish, spread a thin layer of meat sauce on the bottom. Layer noodles, dollops of cream cheese mixture, and sprinkle 1 cup each of mozzarella and parmesan. Repeat layers until all ingredients are used, finishing with sauce and remaining cheese on top.

Cover the lasagna with foil and bake for 40-45 minutes. Remove foil and bake for an additional 5-10 minutes until cheese is melted and edges are crisp.

Remove from the oven and let the lasagna sit for 10 minutes before slicing. This allows the layers to set.