Preheat your oven to 350°F (175°C)
In a large mixing bowl, combine the ground beef, breadcrumbs, onion, bell pepper, eggs, milk, salt, pepper, garlic powder, and onion powder. Mix gently until just combined
Transfer the mixture to a loaf pan or shape it into a loaf on a baking sheet.
Bake in the preheated oven for 45 minutes.
While the meatloaf bakes, whisk together the ketchup, brown sugar, apple cider vinegar, and mustard in a small bowl to make the glaze.
After 45 minutes, remove the meatloaf from the oven and spread the glaze evenly over the top.
Return the meatloaf to the oven and bake for an additional 15–20 minutes, or until the internal temperature reaches 160°F (71°C).
Let the meatloaf rest for 10 minutes before slicing and serving.