In a small saucepan, whisk together hot pepper sauce, ¼ cup Greek yogurt, apple cider vinegar, and ½ tsp garlic powder. Add water as needed. Bring to a simmer over medium heat.
Reduce heat to low and simmer for 5 minutes, whisking frequently. Remove from heat and cool.
In a large bowl, combine shredded chicken, remaining Greek yogurt, cottage cheese, cooled sauce mixture, and mozzarella.
Stir in remaining garlic powder, onion powder, parsley, and 4 tbsp green onions. Mix well.
Pour mixture into an 8×8-inch baking dish. Sprinkle cheddar cheese on top.
Bake 20–25 minutes, until hot and bubbling.
Top with remaining green onions and jalapeño (if using). Serve warm with carrot and celery sticks.