Prepare the Meatballs

1. Preheat the Oven: Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper or lightly grease it to prevent sticking.
2. Make the Meatball Mixture: In a large bowl, combine the ground beef, breadcrumbs, milk, egg, onion, garlic, salt, pepper, oregano, parsley, and red pepper flakes. Mix gently until all ingredients are combined, being careful not to overwork the mixture.
3. Form the Meatballs: Roll the meat mixture into 1 to 1 1/2-inch meatballs and place them on the prepared baking sheet. You should have about 12-14 meatballs, depending on size.
4. Bake the Meatballs: Place the meatballs in the preheated oven and bake for 20-25 minutes, or until they are cooked through and browned on the outside.

Prepare the Dr. Pepper Sauce

1. Cook the Sauce: While the meatballs are baking, add Dr. Pepper, ketchup, brown sugar, soy sauce, Worcestershire sauce, apple cider vinegar, garlic powder, onion powder, and smoked paprika (if using) to a medium saucepan. Stir everything together and bring it to a simmer over medium heat.
2. Thicken the Sauce: Let the sauce simmer for about 15 minutes, stirring occasionally. If you’d like a thicker sauce, mix the cornstarch with water and stir it into the simmering sauce. Continue to cook for a few more minutes until the sauce has thickened to your desired consistency.

Combine the Meatballs and Sauce

1. Toss Meatballs in Sauce: Once the meatballs are done baking, carefully transfer them to the saucepan with the Dr. Pepper sauce. Stir gently to coat each meatball with the sauce.
2. Simmer Together: Let the meatballs simmer in the sauce for an additional 5-10 minutes to absorb the flavors and heat through.