Season the ground beef with salt and pepper. Crumble into a large skillet. Cook over medium heat until fully browned and no pink remains. Drain excess grease and set beef aside.

In a medium bowl, combine the softened cream cheese, sour cream, ricotta, Italian seasoning, and garlic powder. Stir until smooth and uniform.

Pour half a jar of marinara sauce into the slow cooker. Spread it into an even layer.

Layer half the uncooked bowtie pasta over the sauce in a single even layer. Pour the remaining half jar of marinara on top of the pasta.

Fill the empty sauce jar with water and pour half of that water evenly over the pasta layer. Add half the cooked ground beef. Spoon the cream cheese mixture over the beef and spread gently.

Add the remaining pasta in an even layer. Pour the second full jar of marinara over it. Pour the remaining water on top. Finish by spreading the remaining cooked beef across the top.

Cover and cook on low for 2 hours and 30 minutes. Check the pasta; it should be tender but not mushy. If the pasta needs time, cook in 10- to 20-minute increments.

Sprinkle the shredded mozzarella over the pasta. Cover and cook for an additional 20 minutes, or until cheese is melted and bubbly.

Let rest 5 to 10 minutes before serving to let the sauce settle.