Heat oven to 400°F. Grease 14 muffin cups or line with paper baking cups.** In small saucepan over low heat, melt unsweetened chocolate, stirring constantly. Stir in 3 tablespoons of the buttermilk and 1 tablespoon of the oil; blend well.
In large bowl, combine bread mix and cocoa; mix well. Add remaining buttermilk, remaining oil, chocolate mixture, chocolate chips and eggs. Stir just until dry ingredients are moistened. Spoon batter into greased muffin cups.
Bake at 400°F. for 18 to 22 minutes or until tops spring back when lightly touched. Immediately remove from muffin cups. Serve warm or cool.