Buy a good quality, full fat, creamy yoghurt. I like raspberry or coconut yoghurt. Generally a nice fruit yoghurt works better than something like toffee flavour.
Using the yoghurt pot add 1 pot of vegetable, sunflower or corn oil, 2 pots of sugar, 3 pots of flour and 3 eggs. The recipe assumes you're using an individual serving of yoghurt, so I guess if you use a massive pot, you might need to add an extra egg or two.
Because it has egg, oil and yoghurt it should make quite a moist mix.
I've also added frozen fruits to the mix in the past and it came out quite nice but it doesn't really need it.
Put some greaseproof paper into a baking tray or cake tin, spoon the mixture into it and put it in the oven on a medium setting for about 30-40 mins.
Let it cool and then cut into pieces. Store in the fridge. Goes quite well on its own or with a little fresh fruit.