1Crush the digestive biscuits into fine crumbs using a food processor or by placing them in a ziplock bag and crushing with a rolling pin.
Melt the dark chocolate in a heatproof bowl over a pot of simmering water (double boiler method) or in the microwave in 20-second bursts, stirring until smooth. Let it cool slightly.
In a mixing bowl, whip the heavy cream until soft peaks form.
Gently fold the sweetened condensed milk into the whipped cream until well combined.
Pour the melted chocolate into the cream mixture and fold gently until fully incorporated and smooth.
To assemble, layer a spoonful of biscuit crumbs at the bottom of serving glasses, followed by a layer of chocolate cream. Repeat the layers until all ingredients are used, finishing with a layer of chocolate cream on top.
Optionally, garnish with extra biscuit crumbs or chocolate shavings.
Chill the parfaits in the refrigerator for at least 1 hour before serving for best texture.