In a heatproof jug, prepare jelly as per pack instructions. Divide evenly into four glasses, allow jelly to cool before setting in the fridge overnight.
To make the creamy topping, in a mixing bowl, combine the sweetened condensed milk and boiling water. Stir to combine. In a separate smaller bowl, combine the cold water and 2 gelatine packets, stir to mix. Allow the gelatine mixture to set for 2-3 minutes.
Pour the gelatine mixture into the sweetened condensed milk mixture, stir to combine.
Once your jelly is set, add in the creamy layer, making it as thick or thin as you’d like.
Place glasses back into the fridge to set for a couple of hours until the cream layer is set.