This rose tinged, lilting raspberry butterscotch sauce was inspired by raspberry caramels—the creation of pastry chef Marc Aumont of The Modern in New York City. I use Muscovado sugar to give it extra flavor dimension, but any brown sugar is also delicious. It is lovely laced on scones, fruit tarts, or chocolate or other cake, and hard to resist eating by the spoonful. It is also perfect for stabilizing and flavoring whipped cream.