Beat the cream with the sugar with a mixer on low until you get a very thick cream - when you tilt the bowl over it must not fall off.
Dip each biscuit very briefly in the dissolved coffee.
Smear each biscuit with the cream and arrange 4 slices of banana on top. Do this for all of the biscuits. Stack them as high as you like.
Smear the entire roll with cream and decorate with sugar sprinkles.
Cool it in the fridge overnight. Consume the next day.