In a large bowl, add the ground beef, minced garlic, chopped parsley, harissa, salt, paprika, cumin, coriander, sumac, turmeric, fennel, black pepper, garlic powder, and cinnamon.
Use your hands to combine together, making sure not to overwork the meat. This will help to achieve a light fluffy meatball instead of a dense one.
Grab a small handful of meat and push half a mozzarella ball into the center. Use your hands to gently roll the meat into a ball, sealing tightly where the mozzarella ball is nestled into. Repeat until you have around 16 meatballs.
Over medium-high heat, add olive oil into a saute pan or skillet. Once the oil is hot, drop the meatballs in and leave room so that they are not sticking to each other. As they cook on the pan, sprinkle a pinch of salt on each side.
Allow each side of the meatball to get a nice dark brown sear before using a spoon to turn them over. Repeat this process until you have even browning.
Once they're seared perfectly all around, lower the heat and cover for a bit (about 2 minutes) to make sure it's fully cooked to the center.
Garnish with chili flakes for an extra kick and chopped parsley.