Peel the bananas and cut each one in half crosswise. Insert a Popsicle stick into the cut end of each banana half. Place the bananas on a baking sheet lined with parchment paper and freeze until firm.Crush the sugar-free digestive biscuits into fine crumbs. You can do this by placing them in a sealed plastic bag and gently crushing them with a rolling pin. Melt the sugar-free chocolate in a heatproof bowl over a pot of simmering water or in the microwave, stirring occasionally until smooth. Dip each frozen banana half into the melted chocolate, using a spoon to help coat it evenly. Allow any excess chocolate to drip off. Roll the chocolate-coated bananas in the crushed sugar-free digestive biscuits until they are evenly coated. Place the coated banana pops back on the parchment-lined baking sheet and return them to the freezer until the chocolate hardens, about 30 minutes to 1 hour. Once the chocolate is firm, the banana pops are ready to enjoy! Serve them as a delicious and guilt-free frozen treat.