• Line an 8x8 pan with parchment paper.

For the microwave:

• Add the chocolate and peanut butter to a microwave-safe bowl. Microwave at 50% power in 30-second intervals, stir with a rubber spatula each time until melted.
• Pour the chocolate into the 8x8 pan and refrigerate for 1 hour. Cut into pieces and store in the fridge.

For a double boiler:

• Bring water to a boil. Add the chocolate and peanut butter to the top of the double boiler. Stir occasionally with a rubber spatula until it is melted.
• Pour the chocolate into the 8x8 pan and refrigerate for 1 hour. Cut into pieces and store in the fridge.