Butterscotch is one of those old-school ice cream sundae toppings that often seems to get overlooked in favor of sexier, more daring-sounding sauces like olive oil hot fudge and fried chicken caramel. But that's a shame, because its deep, buttery flavor is a perfect foil for a scoop of vanilla. This homemade butterscotch from pastry chef Tracy Obolsky of Manhattan's North End Grill couldn't be simpler: Add all the ingredients to a pot, bring to a simmer, and simmer for four minutes. As it cooks, the milk solids in the butter and cream caramelize along with the brown sugar, giving the finished sauce its signature toasty flavor. A bit of Scotch adds a smoky kick. Let the sauce cool, and you have a perfect sweet-salty topping for ice cream, bread pudding, or any other dessert you can imagine.