01 - Preheat oven to 425°F (220°C). Line a baking sheet with parchment paper.
02 - In a large bowl, combine ground meat, egg, breadcrumbs, minced garlic, finely chopped spring onions, soy sauce, salt, and black pepper. Mix gently until all components are just incorporated to prevent overworking.
03 - Portion the mixture and form into 20 to 24 small meatballs. Arrange evenly on the prepared baking sheet.
04 - Place the baking sheet in the oven and bake for 12 to 15 minutes, until the meatballs are cooked through and well browned.
05 - While the meatballs bake, combine hot sauce, brown sugar, honey, apple cider vinegar, soy sauce, and sriracha (if using) in a saucepan over medium heat. Stir and bring to a gentle simmer, dissolving the sugar completely.
06 - Reduce the heat to low and stir in unsalted butter until fully melted and the sauce appears glossy and smooth.
07 - Transfer the baked meatballs to a large bowl. Pour hot firecracker sauce over and toss carefully to coat all meatballs evenly.
08 - Arrange meatballs for serving and sprinkle with sesame seeds and sliced spring onions. Serve immediately.