Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper for easy cleanup.
In a large mixing bowl, combine the ground beef, egg, almond flour, garlic powder, onion powder, dried oregano, sea salt, and black pepper.
Gently mix the ingredients by hand until just incorporated, taking care not to overwork the meat which can make it tough.
Portion and roll the mixture into approximately 6 to 8 meatballs, roughly 1.5 inches in diameter, and place them on the baking sheet.
Bake the meatballs for 12-15 minutes or until they are browned on the outside and cooked through to an internal temperature of 160°F.
While the meatballs are roasting, pour the marinara sauce into a medium skillet and warm over medium-low heat until simmering.
Add the cooked meatballs to the skillet, tossing gently to coat them in the sauce, and serve garnished with freshly chopped parsley.