Preheat your oven to 350°F (175°C).
Prepare the chicken by boiling or baking until fully cooked, then shred into bite-sized pieces.
In a large mixing bowl, mix softened cream cheese and ranch dressing until smooth. Add garlic powder, onion powder, and black pepper, and stir well.
Fold in shredded chicken, crumbled bacon, frozen mixed vegetables, and cooked pasta until evenly coated.
Transfer the mixture to a greased 9x13 inch baking dish and spread evenly. Sprinkle shredded cheddar cheese on top.
Bake in the preheated oven for 25-30 minutes until cheese is melted and bubbly.
Let cool for a few minutes before garnishing with sliced green onions and serving.