You can, just remember that chocolate chips don't melt down as easily as baking chocolate because they have stabilizers in them to help keep their shape. They also don't make unsweetened chocolate chips so you may need to remove 1 Tablespoon of sugar for every 1 ounce of chocolate chips you use. You can also try this substitute for 1 ounce of unsweetened chocolate: -3 tablespoons cocoa powder + 1 tablespoon vegetable oil or melted shortening