Insert a wooden stick into each banana half. Freeze the bananas and the peanut butter cups for 2 hours.
Meanwhile, heat the chocolate in a double boiler or medium heatproof bowl set over (but not in) a saucepan of simmering water, stirring often, until melted and smooth.
Chop the frozen peanut butter cups. Line a plate with parchment.
Coat the frozen bananas in the melted chocolate. Sprinkle with the chopped peanut butter cups. Freeze on the prepared plate until firm, 4 to 5 minutes.
