Preheat oven to 325 degrees. Trim crusts from bread, if desired, and discard (or put in bird feeder). Mix together margarine, garlic powder, parmesan cheese, and parsley until well blended. Butter each side of each slice of bread. Make a stack of the slices, and use a sharp knife to cut into cubes. Separate the cubes onto a large jelly roll pan or cookie sheet. Bake at 325 degrees. The time will vary. After 10 minutes baking time, stir them with a spatula. Continue baking and stirring every 10 minutes until croutons are evenly brown on all sides. Cool completely, then store in an airtight container. Notes: You can add all sorts of things to the butter to add flavor...Italian spices, dry cheddar from boxed macaroni, the spices from stove-top stuffing...just about anything you're in the mood for. (Notes from Sharon Frye)