For this specialty from her native Piedmont, not published in any of the sources I have seen, I am indebted to my friend Graziella Torti. Bünet is smooth, dark, and delicious, somewhat like a pudding in consistency, but so much silkier and buoyant than puddings ever seem to be. It is best served chilled.
Make the caramel: Put the sugar and water in a small, preferably thin-bottomed saucepan. Turn on the heat to high and melt the sugar until it is a dark brown color. Do not stir, but tilt and rotate the pan to keep the sugar from sticking while it is melting.
The instant the sugar has become caramelized to a dark brown, pour it into the ring mold, turning and ti