Preheat the air fryer: Set to 375°F (190°C) for 5 minutes.
A hot basket helps the meatballs brown quickly.
Cook the bacon: Pan-fry or air fry until crisp, then finely chop. Let it cool so it doesn’t melt the cheese too early.
Prep the cheese: Cut into small cubes, roughly 1/2-inch. Smaller cubes melt evenly and stay tucked inside.
Mix the base: In a large bowl, combine ground meat, breadcrumbs, egg, milk (if using), onion, garlic, parsley, salt, pepper, and smoked paprika.
Mix gently with your hands until just combined. Do not overwork or the meatballs can turn dense.
Fold in bacon: Sprinkle the chopped bacon over the mixture and gently fold to distribute evenly.
Form the meatballs: Scoop about 2 tablespoons of mixture, flatten slightly, place one cheese cube in the center, and wrap the meat around it. Roll into a ball, making sure the cheese is fully sealed. You should get about 16 meatballs.
Lightly oil: Spray the air fryer basket and give the meatballs a quick mist so they crisp without sticking.
Arrange and air fry: Place meatballs in a single layer with space between them.
Air fry at 375°F (190°C) for 10–12 minutes, shaking the basket or turning once halfway. They’re done when the outsides are browned and the internal temperature reaches 165°F (74°C).
Rest and serve: Let them rest 3 minutes to keep the juices in. Serve with marinara, BBQ sauce, or your favorite dip.