Start by placing a rack in the upper third of your oven and preheating it to 400 degrees F. This will ensure that the meatballs cook evenly. Lightly coat a 9×13-inch baking dish or rimmed baking sheet with nonstick cooking spray to prevent sticking.
In a large bowl, beat the egg until smooth. It’s the perfect time to add in the ground chicken, breadcrumbs, Parmesan cheese, 1 tablespoon of olive oil, oregano, garlic powder, onion powder, salt, red pepper flakes, parsley, and 1 tablespoon of tomato paste. Each ingredient plays a crucial role in making these meatballs flavorful.
Finely chop the spinach into small bits and add it to the mixture. This not only adds flavor but also ensures that the meatballs are packed with nutrients.
Now, using a fork or your hands, mix everything together until well combined. Be careful not to compact the meat too much; you want the meatballs to be light and fluffy.
Shape the mixture into 12 equal-sized meatballs. Make sure to arrange them in the prepared baking dish about 1 inch apart, so they don’t touch while baking.
In a small bowl, whisk together the remaining 1 tablespoon of olive oil and 1 tablespoon of tomato paste. It won’t be perfectly smooth, but that’s okay; this mixture will create a lovely glaze on top.
Brush the olive oil and tomato paste mixture over the tops of the meatballs. This step will help them brown beautifully and add more flavor.
Place the baking dish in the oven and bake the meatballs for 18 to 22 minutes. Keep an eye on them; they should be cooked through and golden brown on the outside.
Once they're ready, remove them from the oven and let them cool slightly. Serve hot with your choice of pasta, zucchini noodles, or even stuffed in a bun for a delicious sandwich.