Place 9 tablespoons milk in a microwave-safe bowl.
Add chocolate chips, cocoa, and coffee. Microwave at HIGH for 1 minute or until melted. Stir in 1/2 teaspoon vanilla.
Spread into prepared pan.
Combine the remaining milk, peanut butter chips, and peanut butter in a microwave-safe bowl. Microwave at HIGH for 1 minute or until melted. Stir in remaining 1/2 teaspoon vanilla.
Spread evenly over chocolate layer, and sprinkle with peanuts. Cover and chill 2 hours.