Heat the oven to 375°F. Lightly grease a 12-cup muffin pan with a little of the olive oil.
In a large bowl, combine the ground beef, egg, onion, almond flour, tomato paste, chili powder, cumin, salt, and black pepper. Mix gently until combined.
Divide the beef mixture among 8 muffin cups, filling each about three-quarters full. Press the mixture lightly into the cups. Bake for 20 to 25 minutes, until the muffins are cooked through and browned on top.
While the muffins bake, heat the remaining olive oil in a large skillet over medium heat. Add the riced cauliflower and cook for 6 to 8 minutes, stirring often, until tender and any excess moisture has evaporated.
Make the avocado salsa by gently mixing the diced avocado, lime juice, jalapeño, and half of the chopped cilantro in a small bowl.
Let the meatloaf muffins rest for a few minutes. Serve them over the cauliflower rice, topped with avocado salsa and the remaining cilantro.