1Cook the ground beef in a skillet and drain excess grease.
2Add the ground beef, marinara sauce, half the mozzarella cheese, half the parmesan cheese, garlic powder, Italian seasoning, salt, and pepper to the crockpot.
3Stir to combine.
4Top with the remaining cheeses and turkey pepperoni slices.
5Cook on low for 4 hrs until the cheese is melted and bubbly.