Preheat your oven to 350°F (175°C) and grease a loaf pan or line it with parchment paper.

Heat olive oil in a skillet over medium heat. Sauté chopped onion and bell pepper until softened, about 5 minutes.

Let the sautéed vegetables cool slightly, then mix with ground beef, garlic powder, crushed crackers, beaten eggs, cheese, milk, salt, and black pepper in a bowl until just combined.

Shape the mixture into a loaf and place in the prepared pan.

Mix ketchup, balsamic vinegar, brown sugar, and yellow mustard in a small bowl for the glaze.

Spread half of the glaze over the meatloaf and bake for 45 minutes.

After 45 minutes, spread the remaining glaze on top and bake for an additional 15 minutes or until the internal temperature reaches 160°F (71°C).

Let the meatloaf rest for 10 minutes before slicing.