Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper and spray it generously with non-stick cooking spray.

In a large bowl, combine the panko breadcrumbs, milk, kosher salt, garlic powder, egg, and olive oil. Stir everything together and let the mixture sit for 2 to 3 minutes so the breadcrumbs absorb the liquid and become cohesive.

Add the ground chicken and Parmesan cheese to the soaked breadcrumb mixture. Mix until everything just comes together. Do not overmix or the meatballs can turn dense.

Lightly wet your hands to prevent sticking, then scoop and roll the mixture into 18 to 20 evenly sized balls. A cookie scoop works great for consistent sizing.

Place the meatballs on the prepared baking sheet with a little space between each. Lightly spray the tops with cooking spray for a golden finish.

Bake for 20 minutes. For extra color, switch on the broiler for the last 2 to 3 minutes and watch closely. The meatballs are done when cooked through and golden on the outside. Internal temperature should reach 165°F.