In a skillet over medium heat, brown the ground beef with Italian seasoning, garlic powder, salt, and pepper. Drain off any excess grease.

Spread half of the crushed tomatoes on the bottom of your slow cooker.

Layer 3 lasagna noodles on top of the tomatoes. Break them to fit if necessary.

Spread half of the cooked ground beef mixture over the noodles.

In a small bowl, mix together the ricotta cheese and the egg. Spread half of this mixture over the beef.

Repeat the layers: remaining crushed tomatoes, 3 lasagna noodles, remaining ground beef, and remaining ricotta mixture.

Top with the remaining 3 lasagna noodles and the shredded mozzarella cheese.

Cover and cook on low for 3-4 hours or on high for 1.5-2 hours, until noodles are tender and cheese is melted and bubbly.

Let stand for 10 minutes before serving. Sprinkle with grated Parmesan cheese.