Brown beef with onion and garlic in a large skillet over medium-high 8-10 minutes until fully cooked with no pink; drain excess fat.
Transfer to slow cooker; stir in beans, tomatoes, tomato sauce, broth, chili powder, cumin, paprika, salt, and pepper.
Cover; cook on LOW 3-4 hours or HIGH 2-3 hours, stirring occasionally if possible.
About 30 minutes before serving, stir in uncooked macaroni, fully submerging it. Cover and cook until tender.
Stir in half the cheddar and Monterey Jack until melted and creamy.
Serve hot topped with remaining cheese and favorite toppings such as sour cream, green onions, or jalapeƱos if desired.