Brew your coffee, transfer to a small bowl and allow to cool
In a large bowl, beat the double cream, condensed milk and mascarpone until the mixture resembles whipped cream
Dunk the savoiardi briefly into the coffee, making sure they are fully immersed (1 second on each side)
Arrange half of the soaked biscuits in a row on the base of a 700ml (or larger) tupperware
Gently spoon and smooth half of the ice cream mix onto the layer of soaked biscuits
Repeat with the remaining biscuits and finish with a second layer of ice cream mix
Dust with cocoa powder, cover and freeze for 5 hours, or overnight
Remove from the freezer about 15 minutes before serving to allow it to soften slightly
