In place of powdered peanut butter, you can use more protein powder or even 5 tablespoons (25 g) of unsweetened cocoa powder for a chocolate variety. (glutenfreeonashoestring.com)
Mix together 1 tablespoon of cocoa powder with 1 tablespoon of water. (the-farmersdaughter.com)
Warm 1 cup of cream with cocoa powder in medium saucepan, whisking to thoroughly blend the cocoa. (userealbutter.com)