This is what I usually make for my family every morning since we don't have time to sit on the table and eat a complete breakfast. I just leave this on the table for them to grab as an 'on-the-go' breakfast. My lunchtime, it's all gone!
Heat oven to 400°F Grease bottoms only of 12 regular-size muffins cups with shortening or cooking spray, or line muffin cups with paper baking cups.
In a medium bowl, Mix flour, cocoa, baking powder, and salt; set aside. In large bowl, beat brown sugar, milk, oil, coffee and egg with fork or wire whisk. Stir in flour mixture just until flour is moistened. Fold in chocolate chips. Divide batter evenly among cups.
Bake 18 to 20 minutes or until toothpick inserted in the center comes out clean. When done, immediately move muffins from pan to cooling rack.