Preheat the oven to 350° F. Line a sheet pan with foil (for easy cleanup) and grease the foil.
In a medium bowl, whisk together the egg, salt, pepper, garlic powder, onion powder, and smoked paprika.
Add the ground beef, almond flour, and parmesan. Gently mix, just until uniform.
Divide the beef mixture into two halves. Form one half into a roughly 8-by-4-inch rectangle (you can use a clingwrap-lined loaf pan as your mold, as shown in the video below) and place the rectangle on the prepared baking sheet. Place the hard-boiled eggs, evenly spaced, on top.
Place the second half of the beef mixture on top of the eggs. Press it so that it adheres to the bottom layer. With your fingers, pinch the edges of the two rectangles together to create one meatloaf. Pinch well to prevent the meatloaf from bursting at the seams as it bakes. You can transfer pinches of ground beef to sparse areas where eggs are peeking or where it's difficult to pinch the edges together.
Brush the meatloaf with ketchup.
Bake until the center of the loaf registers 160°F, 50-60 minutes.
Rest the meatloaf for 15 minutes before slicing and serving.
Video
Notes
When making this recipe, you will need to break one of the basic rules of making meatloaf - handling the meat minimally and lightly to keep the meatloaf from becoming too dense. In this case, since it's important to make sure that the two layers of the meatloaf stick together, you will need to work the meat for as long as it takes until you're sure it will stay together and not burst at the seams while baking. Surprisingly, even with this much handling, this meatloaf is not too dense.
If you don't mind the carbs, you can replace the almond flour with breadcrumbs (gluten-free if needed) and use two large eggs.
For the ground beef, the leanest you should go is 85/15. Leaner than that would result in a dry meatloaf.
You can keep the leftovers in an airtight container in the fridge for 3-4 days. Reheat them in the microwave, covered, at 50% power, or serve them cold.