Grease a 13x9 baking dish and preheat oven to 350 degrees.
Combine all ingredients except ketchup in a large bowl, and mix thoroughly either with clean hands or a large wooden spoon. Mix until everything holds together and there are no loose breadcrumbs or oats in the bottom of the bowl.
Form the meatloaf mixture into two large loaves and place side-by-side in the greased baking dish. Spread ketchup evenly over the tops of both meatloaves. (It's easier if you use a squeeze-type bottle and just squeeze it right on!)
Bake meatloaves, uncovered, at 350 for 1 to 1 1/2 hours. If you like a darker crust, you can up the temperature to 375 toward the end. Bake until the center of each loaf reaches 165 degrees when tested with a meat thermometer, or until juices run clear when you insert knife in the center of each loaf.
Remove from the oven and allow meatloaves to rest 10 minutes before slicing and serving. Enjoy!