This Pot de Creme is like a turbo-charged version of butterscotch pudding. The texture is like silk and the taste is sweet, with just a slight bitter edge from the burnt sugar in the butterscotch. Cooking the butter and brown sugar together until it is smoking hot is the key to the flavor. If you don’t bring them to the brink of burning, the pudding will be way too sweet for my taste. The creme fraiche (young sour cream) is unsweetened and the perfect balance for the pudding.