For oven preparation, heat the oven to 375°F. Line a baking sheet with parchment paper, a silicone baking mat, or aluminum foil to reduce sticking and simplify cleanup.
For air-fryer preparation, preheat the appliance to 350°F.
Add the baking mix and sliced green onion tops.
Blend the ingredients thoroughly with clean hands, a sturdy spoon, or a stand mixer until the cheeses, onions, and baking mix are evenly incorporated throughout the sausage. When mixing by hand, gently fold and knead the mixture until no dry pockets remain.
Using a medium cookie scoop or a generous tablespoon, divide the mixture into 24 equal portions.
Roll each portion into a ball approximately the size of a golf ball. Arrange the balls on the prepared baking sheet with a small amount of space between them.
For oven baking, cook at 375°F for 15–20 minutes, or until the sausage balls are lightly browned and fully cooked.
For air frying, cook at 350°F for 10–15 minutes. Shake the basket after approximately 5 minutes to encourage even browning.
Check the center of the sausage balls with an instant-read thermometer. Ground turkey should reach an internal temperature of 165°F.
Serve warm with marinara sauce, barbecue sauce, or another preferred dipping sauce.