Add the chocolate chips, butter and peanut butter in a shallow bowl. Cover and microwave for 1 minute.
Stir, cover again, and microwave for 30 more seconds. Stir to incorporate, then stir in the stevia.
Cover and freeze the mixture for 30 minutes.
Using a measuring tablespoon, one tablespoon per truffle, form the mixture into 12 truffles. Roll them in cocoa powder to coat. You’ll only use half the cocoa powder but you need all of it to properly coat the truffles.