In a small microwave-safe mixing bowl, beat cream cheese and garlic powder until smooth. Stir in spinach and Swiss cheese. Cover; microwave on high for 5–8 minutes or until cheese is melted, stirring occasionally.
Meanwhile, cut a 4-inch circle in the center of one loaf of bread. Remove bread, leaving 1 inch at bottom of loaf. Cut removed bread and the second loaf into 11⁄2-inch cubes. Spoon hot spinach dip into bread shell. Serve with bread cubes.