Preheat oven to 350 degrees. Spray one 9×13 and one 9×9 glass dish with nonstick cooking spray and set aside.
In a large bowl, add spaghetti and butter and toss gently. Mix chicken and next 7 ingredients; toss gently. Combine flour and sherry in medium bowl, beating well with a wire whisk. Add broth, half and half, and garlic powder; stir well. Pour over spaghetti mixture; stir gently.
Spoon into baking dish. Sprinkle evenly with cheese, seasoned salt, almonds and breadcrumbs.
Bake at 350 degrees for 45 minutes. Cover with foil and bake an additional 10-12 minutes or until bubbly.