Form the mixture into 1-inch (2.5-cm) meatballs and place on the lined baking sheet.
Preheat the oven to 400 degrees F (204 degrees C). Line a baking sheet with parchment paper or a silicone mat.
In a large bowl, whisk together the parmesan cheese, almond flour, egg, buffalo sauce, salt, and pepper. Fold in the blue cheese and green onions.
Add the ground chicken. Mix until just combined. (Don’t overmix.)
Meanwhile, in a small bowl in the microwave or a small saucepan on the stove, heat the buffalo sauce and butter together, until melted. Whisk until smooth and hot.
When the buffalo chicken meatballs are done, gently toss them with the buffalo sauce mixture. If you like, serve them with a drizzle of ranch dressing, extra blue cheese crumbles, and extra green onions.