Preheat the oven to 400°F (200°C). Spray a metal roasting pan with cooking oil spray.
Put the elk, pork, eggs, almond flour, chopped onion, soy sauce, parsley, basil, tomato paste, garlic powder, salt, and pepper in a large mixing bowl. Mix everything together well with clean hands.
Shape the meat mixture into a large loaf in the prepared roasting pan. You want it to be about 8½ inches long and 1-1¼ inches tall (21.6 cm long and 2.54-3.2 cm tall).
Put the meatloaf on an oven rack about ⅓ of the way from the top of the oven. Bake for 50 minutes at 400°F (200°C).
Brush the ketchup all over the top and sides of the meatloaf and bake an additional 5-10 minutes.
Check the meatloaf with a meat thermometer to ensure it has reached the minimum safe internal temp of 160°F (71°C). Extend the cooking time if needed.
Let the meatloaf rest for 10 minutes before slicing and serving.