Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a large bowl, combine the ground beef, ground pork, breadcrumbs, Parmesan cheese, cheddar cheese, bacon, onion, garlic, egg, Worcestershire sauce, smoked paprika, salt, black pepper, and cayenne pepper, if using.
Mix the ingredients until well combined, but avoid overmixing to keep the meatballs tender.
Using your hands, form the mixture into meatballs, about 1.5 inches in diameter, and place them on the prepared baking sheet.
Bake the meatballs in the preheated oven for 20-25 minutes, or until they are cooked through and golden brown.
Remove from the oven and let the meatballs rest for a few minutes before serving.
Garnish with chopped parsley and serve with your favorite dipping sauce or in a sub sandwich.