Butterscotch evokes memories of an old-fashioned ice cream sundae from a charming small-town soda fountain. It’s a flavor that doesn’t get enough attention, which is a good reason to make these lovely custards, bursting with the tastes of brown sugar, butter and a hint of whisky.
Custards are delicate, and to keep them smooth and silky (and not overbaked and curdled!) it’s important to bake them at a low temperature and ideally in a water bath, which helps insulate the custard. Check the custard regularly, ,and take it out while it still jiggles.
3 Tbs. unsalted butter
3/4 cup (6 oz./185 g.) lightly packed dark brown sugar
1 1/2 cups (12 fl. oz./375 ml.) heavy cream
3/4 cup (6 fl. oz./180 ml.) whole mnilk
5 large egg yolks, lightly beaten
1 tsp. pure vanilla extract
1 Tbs. whisky, preferably a sweet Scotch (optional)
1/4 tsp. kosher salt
Whipped cream for serving
Position a rack in the middle of the oven and preheat to 300 degrees F (150 degrees C). Have ready six 1/2-cut (4-fl. oz./125-ml.) custard cups or ramekins and a shallow baking pan large enough to hold all the cups.
In a medium saucepan, melt the butter over medium-low heat. Add the brown sugar and, using a heatproof rubber spatula, stir to combine with the butter and cook until the sugar starts bubbling like molten lava, about 3 minutes. Stir in the cream, and let it bubble away, stirring with a big whisk until the mixture is smooth and slightly thickened, about 5 minutes. Stir in the milk.
Whisking constantly, slowly pour the egg yolks into the hot cream mixture. Stir in the vanilla, whisky, if using, and salt. Pour the custard through a fine-mesh sieve into a pitcher.
Divide the custard evenly among the custard cups. Place the cups in the baking pan and carefully pour hot water into the pan to reach halfway up the sides of the cups (we recommend adding the water once you place the pan on the oven rack). Bake until the custards are set but still jiggle slightly when shaken, 25-30 minutes.
Carefully transfer the baking pan to a wire rack and let the custards cool slightly, then carefully lift the cups out of the water bath. Let the custards cool on the wire rack for 20 minutes. Cover with plastic wrap pressed directly onto the surface of the custards to prevent a skin from forming. Refrigerate until the custards are well chilled, about 4 hours or up to overnight.
Serve cold with dollops of whipped cream. Makes 6 custards.