Adapted our favourite family recipe by substituting dextrose for the sugar. Turned out ok. 

Refrigerate a tin of evaporated milk for at least 24 hours( i just put in fridge when I buy it)

Beat evaporated milk and 1 cup dextrose until it is thick and about double in size.

Divide mixture in half.

Mix 3 teaspoons of gelatine with about 1/4 cup boiling water, until gelatine is dissolved.  Add 3 tspns of coffee to gelatine mixture. then add it to one half of the milk mixture, and mix through until just combined, can do with mixmaster, dont overbeat. Put into a bowl or a springform tin and put into fridge.

Mix 3 teaspoons of gelatine with 1/4 cup boiling water and dissolve gelatine as before. Add 3 dessertspoons of cocoa to the gelatine mix and then add to the other half of milk mixture. Pour on top of the coffee half, and put back in the fridge until set. If in a bowl top with cream.  If using springform tin, turn out onto a plate, may need to dip in hot water to release tin. Top with cream and serve.