Start by gathering all your ingredients. Preheat your oven to 350°F (175°C). You want everything at your fingertips to keep the momentum going.
In a medium skillet over medium heat, add the olive oil, chopped onions, and bell peppers. Cook until the onions are translucent and the peppers are soft, about 4-5 minutes. This brings out their natural sweetness and flavor.
In a large bowl, combine ground beef, sautéed vegetables, crushed crackers, diced cheese, beaten eggs, milk, Worcestershire sauce, salt, and pepper.
Use your hands (or a sturdy spoon) to mix until everything is just combined. Be careful not to over-mix; this keeps your meatloaf tender.
Transfer the mixture to a baking dish or form it into a loaf shape in a lined pan. Gently press it down to avoid air pockets. It should be shaped like a loaf but can be flattened slightly for even cooking.
In a separate bowl, mix together the ketchup, brown sugar, mustard, and apple cider vinegar. Spread this mixture evenly on top of the meatloaf for an irresistible glaze.
Place the meatloaf in your preheated oven and bake for 1 hour, or until the internal temperature reaches 160°F (70°C). Let it rest for about 10 minutes before slicing. This allows the juices to redistribute, keeping it moist.
