Heat the oven to 400°F. Line a rimmed baking sheet with parchment paper. Toss the broccoli florets with the olive oil, then spread them over one side of the baking sheet.
In a large bowl, combine the ground beef, egg, almond flour, chopped onion, garlic powder, smoked paprika, salt, and black pepper. Mix gently until just combined, then fold in the shredded cheddar.
Divide the beef mixture into eight portions and shape each into a compact mound. Arrange them on the baking sheet beside the broccoli, leaving space between each portion.
Brush the tops of the beef portions with half of the barbecue sauce. Bake for 15 minutes, then brush with the remaining sauce. Continue baking until the beef is cooked through and the broccoli is tender with browned edges, about 8 to 12 minutes more.
Let the meatloaf muffins rest for a few minutes before serving with the roasted broccoli.