In another bowl, mix milk and coffee granules until dissolved.
Add margarine, egg and vanilla; mix well. Stir in flour mixture. Fold in chocolate chips.
Fill muffin liners 2/3 full. Bake at 375° for 17-20 minutes For frosting, beat cream cheese, sugar, coffee granules and vanilla until smooth. Fold in chocolate chips.
Frost cooled muffins with Espresso Frosting.