Preheat oven to 350°F
In a large mixing bowl combine ground beef, diced onion, diced peppers, egg, milk, crackers and 8 ounces of ketchup with a handheld meat grinder or fork
Transfer the meat mixture to a bread loaf pan and gently press it down to form an even layer
Pour the remaining 4 ounces of ketchup on top of the meat, use a spoon if needed to spread it out
Sprinkle the brown sugar on top of the ketchup, use a fork to incorporate the brown sugar into the ketchup
Bake in the preheated oven for 45 minutes. Check the internal temperature of the meatloaf (it should reach 160°F for safe consumption). If needed, continue baking in 5-minute increments until done
Remove from oven and let rest for a few minutes before slicing
Serve and enjoy!