Line a 24-cup mini-muffin pan with candy cups. In a stainless bowl set over a pot of simmering water, mix the chocolate chips and butter until the mixture is melted and smooth.
Spoon 1 teaspoon (5 ml) chocolate inside each candy cup. Chill for 30 minutes, or until cool and solid.
In a medium bowl, beat the peanut butter, butter, bourbon, powdered sugar, and salt until well incorporated and light. Spoon 1 heaped teaspoon (5 ml) peanut butter mixture over the hardened bottom layer of chocolate and press down to level the peanut butter layer.
Add another teaspoon (5 ml) over the peanut butter, allowing the chocolate to completely cover it. If the chocolate mixture has cooled and is no longer pourable, reheat until smooth, then pour over the peanut butter layer. Top each cup with a roasted peanut, if desired.
Chill for 2 hours, or until firm. Store in an airtight container in the fridge for up to two weeks.