01 - Preheat oven to 400°F. Line a baking sheet with parchment paper or lightly grease it.
02 - Combine ground chicken, panko, egg, green onions, garlic, soy sauce, sriracha, salt, and pepper in a large bowl. Mix gently until just combined.
03 - Using damp hands or a cookie scoop, form mixture into 1.5-inch meatballs and place on prepared baking sheet.
04 - Bake meatballs for 18-20 minutes until golden and cooked through.
05 - Combine hot sauce, brown sugar, apple cider vinegar, honey, and red pepper flakes in a small saucepan over medium heat. Simmer for 3-4 minutes, stirring, until slightly thickened. Remove from heat and whisk in melted butter.
06 - Transfer cooked meatballs to a large bowl. Pour firecracker sauce over meatballs and toss gently to coat.
07 - Sprinkle with sesame seeds and sliced green onions before serving.