Preheat your oven to 375°F. Line a baking sheet with foil for easy cleanup and spray with cooking spray (or just spray the baking sheet directly).

In a large bowl, combine all the meatball ingredients. Gently mix everything together using clean hands or a wooden spoon. Pro tip: Don't overmix the meat mixture, as this can make your meatballs tougher.

Use a medium-sized scoop (about 1 to 2 tablespoons) to form approximately 32 meatballs.

Arrange the meatballs evenly on the prepared baking sheet and bake for about 15 minutes, or until fully cooked. Baking Tip: Since the meatballs are small, they should be done in around 15 minutes. If your meatballs are a bit bigger, they may need up to 20 minutes, so keep an eye on them until they're perfectly cooked.

Spray a 2.5 to 3-quart casserole dish (or a 9x13-inch pan) with cooking spray, and add the cooked meatballs. Make-Ahead Tip: If you're prepping ahead, this is the ideal stopping point. Cover the dish tightly and refrigerate for up to 48 hours before finishing the rest of the recipe.

Pour the marinara sauce evenly over the meatballs.

Sprinkle both the mozzarella and Parmesan cheeses over the top.

Bake uncovered for 10 to 15 minutes, or until the cheese is fully melted and turns a light golden brown.

For an extra touch, garnish with fresh herbs before serving.