*Peanut butter chips can easily seize or burn in the microwave. If you don’t have a double boiler, you can easily make one by setting a heatproof mixing bowl on top of a pot of simmering water. Fill a pot with 2 to 3 inches of water and put it over medium heat. Bring the water to a boil and lower the heat to a simmer. Add chips and peanut butter to the bowl and stir until smooth.