In a large skillet over medium-high heat, brown the ground beef along with the chopped onion, stirring until no pink remains, about 6–8 minutes. Drain excess grease and add minced garlic, cooking for an additional minute until fragrant.

Stir in crushed tomatoes into the skillet with cooked beef. Bring to a simmer, reduce heat to medium-low, and cook for 25–30 minutes while stirring occasionally.

Bring a large pot of salted water to a boil. Add lasagna noodles and cook until al dente according to package instructions, typically around 8–10 minutes. Drain and lay flat on a towel.

In a mixing bowl, combine softened cream cheese, cottage cheese (or ricotta), and beaten egg. Blend until smooth and creamy.

In a greased baking dish, spread a thin layer of meat sauce, place lasagna noodles over sauce, followed by half of the cheese mixture, and a sprinkle of shredded mozzarella cheese. Repeat layering and finish with remaining meat sauce, mozzarella, and Parmesan cheese.

Preheat oven to 350°F (175°C). Cover lasagna with foil and bake for 45 minutes. Uncover and bake for an additional 10 minutes until cheese is bubbly and golden brown.

After baking, let lasagna rest for 10 minutes before slicing. Serve warm.