Preheat your oven to 375°F and lightly oil a loaf pan. While the oven heats, prepare all your ingredients: finely dice the onion and carrot into uniform 1/4 to 1/2-inch pieces, mince the garlic, and chop the fresh parsley. I like to do all my prep work with a sharp knife rather than a food processor for vegetables—it gives you better control over the texture and keeps the vegetables from becoming too wet. Place all prepped ingredients in separate small bowls or on a cutting board for easy access.

Pulse the saltine crackers in a food processor until they reach a fine, uniform crumb consistency (about 1 cup). In a large mixing bowl, combine the ground beef with the saltine crumbs, then add the prepared diced onion, carrot, and minced garlic along with the fresh parsley. This order matters because the vegetables and crackers will begin to absorb moisture from the beef, which helps distribute flavors evenly.

Add the room temperature egg, 1/4 cup ketchup, Worcestershire sauce, Dijon mustard, coarse salt, and freshly ground pepper to the beef mixture. Mix gently but thoroughly with your hands or a large spoon until all ingredients are just combined and evenly distributed. Don't overmix—this can lead to a dense, tough meatloaf. I stop mixing as soon as I no longer see any streaks of unmixed ingredients, which usually takes about one minute of gentle folding.

Transfer the meatloaf mixture into the prepared loaf pan, pressing it gently and evenly to eliminate air pockets but not compacting it so much that it becomes dense. In a separate small bowl, whisk together 1/4 cup ketchup, 1 tsp Dijon mustard, and 1 tbsp packed brown sugar until smooth and well combined. Spread about three-quarters of this glaze over the top of the meatloaf using a spoon or brush, reserving a little glaze to add after baking if desired.

Place the meatloaf in the preheated 375°F oven and bake for approximately 55 to 60 minutes, or until the internal temperature reaches 160°F when measured with a meat thermometer inserted into the center of the loaf. This temperature ensures the meatloaf is safely cooked while still remaining moist and tender. If desired, brush the remaining glaze on the meatloaf during the last 5 minutes of baking for added shine and flavor.

Remove the meatloaf from the oven and let it rest in the pan for at least 10 minutes before slicing. This resting period allows the juices to redistribute throughout the meat, ensuring each slice stays moist and tender rather than dry. After resting, you can slice the meatloaf directly in the pan or carefully turn it out onto a cutting board for cleaner presentation.