In a large mixing bowl, add the confectioners’ sugar, peanut butter and butter. Use an electric mixer to blend until well combined and creamy.
Roll the mixture into 1-inch balls. Insert a toothpick into each ball and place on a couple of plates or a baking sheet and freeze for two hours.
Just before removing the cookies from the freezer, place a small saucepan with a few inches of water on the stove, and nest a metal or heatproof bowl into the top of the pot so that the bottom of the bowl is suspended over the water. Add the chocolate chips to the bowl and bring the water to a simmer over medium heat, stirring the chips often until they are melted (see Note).
Place a piece of parchment or wax paper into a couple of shallow containers with flat bottoms. Pour the hot chocolate into a mug or cup. Remove the cookies from the freezer and dip each ball into the chocolate. Place them, not touching, into the containers. Refrigerate until set. These will keep for 2 weeks in the fridge. Remove from the fridge at least 15 minutes before serving.
Alternately you can melt chocolate in the microwave. Place the chips into a microwave safe bowl and place in the microwave. Heat in 15-second bursts, stirring between the heating periods, until the chips are almost entirely melted. Then just keep stirring until the chips are melted and the chocolate is smooth.