Anyway - so I made this as an experiment and it turned out pretty well. It got fed to several non-vegans who all oohed and ahhed about it, and it is in fact so rich that you can't eat it on its own - you have to put fruit and/or vanilla custard with it to try to "dilute" it a bit. At the moment it's 10.8% fat, and I'm thinking it would be possible to reduce that by increasing the ratio of cocoa powder: melted chocolate, and actually removing some of the chocolate altogether as it just doesn't need that much flavour. Treat this as a work in progress.
2 packets of silken tofu (@ 349 g drained weight each)
1 pot of Alpro vanilla soya dessert (@ 125 g - basically, a thick vanilla custard)
200g Green & Black's cooking chocolate (72% cocoa solids)
100g Green & Black's organic fairtrade cocoa
150g icing sugar
You need a blender or food processor. In my opinion, it will be impossible to make this without.
1. Drain the tofu, rinse with cold water, pat dry with kitchen towel.
2. Cut the tofu into small chunks around 3 x 2 cm (or about 1 inch square).
3. Toss them into the blender and whizz until completely smooth. (This took about 8 minutes in ours, including pulsing and stopping every so often to scrape the sides down).
4. Break the chocolate into small pieces and melt carefully in a large glass bowl in the microwave, with much stirring. (Note it is remarkably easy to burn chocolate, because it holds its shape even when almost molten, so you can easily think it's still solid and needs a lot more heat to get melting.)
5. Sieve the cocoa powder and icing sugar into the chocolate and stir well.
6. Add the whizzed tofu and soya dessert to the chocolate and stir until all lumps have gone. Don't be afraid to put the bowl back in the microwave for 15-20 seconds every so often to re-melt the mixture together.
7. Put the mixture into a dish that's safe for refridgeration, and leave overnight.
Even when chilled, it doesn't set as well as the original tofu cheesecake recipe I had does, but you can just call it a mousse instead of a cheesecake. It is, by the way, equally edible hot or cold.
I'm planning to make the next batch with 100g of cooking chocolate + 150g cocoa powder. I'll let you know if that works. Further experiments may involve swapping out the vanilla soya dessert with caramel flavour, or replacing some of the icing sugar with strawberry jam. (I had a chocolate strawberry tofu cheesecake in New York that was made that way, and it was GORGEOUS.)
Oh yes, in case anyone cares, the fat breakdown:
tofu - 17.5g
vanilla dessert - 2.25g
chocolate - 89.4g
cocoa powder - 22.5g
total fat = 131.65g
total mass of cheesecake = 1223g
therefore, percentage fat = 10.8%