Preheat your oven to 400°F and line a baking sheet with parchment paper. Combine ground beef, breadcrumbs, eggs, milk, garlic powder, onion powder, salt, and pepper in a large bowl until just mixed—don't overmix, as this creates dense meatballs.

Using a cookie scoop or your hands, roll mixture into 24 meatballs about 1.5 inches wide. Arrange them on the prepared baking sheet in a single layer, spacing them an inch apart so heat circulates evenly.

Bake meatballs for 12-15 minutes until lightly browned. While they bake, whisk together ketchup, apple cider vinegar, brown sugar, soy sauce, Dijon mustard, and ginger powder in a small saucepan over medium heat.

Once the meatballs reach golden brown, transfer them to the saucepan with the easy sweet sour cocktail meatballs recipe sauce. Stir gently to coat all meatballs evenly in the glaze.

Mix cornstarch with water to create a slurry and stir it into the saucepan. Simmer for 2-3 minutes until the sauce thickens and coats the back of a spoon, creating that signature glossy finish.

Taste the sweet and sour meatballs and adjust seasoning with salt or vinegar as needed. Transfer to a slow cooker set on warm, or serve immediately in a chafing dish for optimal presentation at your party.