I was hunting for a quick chocolate sauce recipe that involved cocoa rather than real chocolate, and didn't require exotic things that I don't have in my cupboard like chocolate, evaporated milk, condensed milk or cream.
Here's one I adapted and it's yummy!
1 cup raw caster sugar
3 tablespoons cocoa
3 tablespoons cornflour
1 cup cold water
half a teaspoon vanilla extract
60 grams salted butter
You can sieve the dried stuff if you like but I just combined them in a saucepan and banged out the lumps with a wooden spoon. Add cold water and vanilla, mix, then dump the chunk of butter in. Stir on medium heat while watching the butter melt (very Zen) and quite soon after the sauce will thicken. Yummo, and in less than ten minutes.
Have just used it to trick my toddler into eating bananas.
You can put the rest in the fridge and it turns into a thick fudge that you can stir into ice-cream for a rather decadent sundae type concoction.