In a small bowl stir together cream cheese, garlic powder, salt, and pepper
Squeeze all excess moisture out of spinach.
Add spinach, pepper, and onion to cream cheese. Stir well.
Spread mixture on tortilla.
Starting at one edge roll tightly. Wrap in plastic and refrigerate for 2 hours.
Preheat oven to 400.
Remove roll from refrigerator. Unwrap and cut into 1-inch slices.
Place slices cut side down on a baking tray and top with a small amount of cheddar cheese.
Bake for 10 minutes.