Preheat the oven to 350 degrees F (175 degrees C). Gather all ingredients.
Melt butter in a skillet over medium heat, and cook onion and garlic until onion is soft and translucent, about 5 minutes. Remove from heat, and season with salt and pepper.
Combine onion and garlic mixture, beef, crumbled bread, crushed crackers, egg, sour cream, Worcestershire sauce, and ½ can tomato sauce in a large bowl. Mix until well combined. Gradually stir in milk, 1 teaspoon at a time, until mixture is moist, but not soggy.
Transfer the mixture to a 5x9-inch loaf pan. Bake uncovered in the preheated oven for 40 minutes. Increase oven temperature to 400 degrees F (200 degrees C). Continue baking 15 minutes, to an internal temperature of 160 degrees F (70 degrees C).
Mix the remaining tomato sauce and ketchup in a small bowl. Pour over the top of the meatloaf, and continue baking for 10 minutes.
Serve hot and enjoy!
