Grab a microwave-safe container (preferably a small one; I used a plastic cup) and toss in the baking chocolate.
Add the coconut oil and peanut butter. I used Peter Pan peanut butter because it was all I could find, but my favorite brand is Skippy's Natural Creamy Peanut Butter.
Add the sweetener and microwave for 60 seconds. Then stir it up into a nice liquid consistency. Freeze for future use.
When ready to use, just plop the cube into the bottom of a cup and pour the coffee straight over the top.