In a large mixing bowl, combine the ground beef, shredded cheddar cheese, Parmesan cheese, diced onion, minced garlic, egg, breadcrumbs, salt, and pepper. Mix gently until just combined.

Divide the meat mixture into 12 equal portions and roll them into smooth balls.

Wrap a slice of bacon around each meatball and secure if needed with a toothpick.

Preheat your oven to 400°F (200°C) and prepare a baking sheet lined with parchment paper.

Place the bacon-wrapped bombs on the baking sheet and bake for 15 to 20 minutes until bacon is crispy and beef is cooked through.

Cool for a minute before serving warm with your favorite dipping sauces.