Bring a large pot of lightly salted water to a boil. Cook spaghetti in the boiling water, stirring occasionally, until tender yet firm to the bite, about 12 minutes. Drain.
Preheat the oven to 350 degrees F (175 degrees C).
While pasta is cooking, cook ground beef in a skillet over medium heat until browned and crumbly, about 7 minutes. Add spaghetti sauce and stir to combine.
Place cubed cheese in a large microwave-safe bowl. Microwave in 1-minute increments, stirring after each minute, until at least halfway melted, 2 to 3 minutes. Mix cooked spaghetti into melted cheese. Add eggs and mix well.
Transfer the pasta mixture into a 9x13-inch baking pan. Pour beef mixture on top, then cover with mozzarella cheese.
Bake in the preheated oven until bubbling, about 20 minutes.