This dessert is really pretty easy and simple to make. First of all, you would need to make the butterscotch by melting the butter over low heat and adding in the brown sugar, cook until the sugar starts to bubble, then the cream is added in. Stir until the mixture is smooth and slightly thickened, then pour in the milk. Stirring constantly, slowly pour in the lightly beaten egg yolks. Add in the vanilla extract, whisky and salt. Pour the custard mixture through a fine-mesh strainer into a pitcher.
Divide the mixture evenly among the custard cups, place in a baking tray, and fill the tray with hot water to reach halfway up the sides of the custard cups. Bake for 25-30 minutes, until the custard is set and will still jiggle slightly when the cups are lightly shaken. Let the custard cool slightly, remove the cups from the water bath, let cool on wire rack for about 20 minutes. Cover the top of each custard by pressing a piece of plastic directly on top of the custard to prevent a skin from forming. Chill the custards for a minimum of 4 hours or overnight.
(adapted from "Home Baked Comfort" by Kim Laidlaw)
Makes 6 custards
3 tbsp unsalted butter
3/4 cup (6oz/185gm) lightly packed dark brown sugar
1-1/2 cups (12fl oz/375ml) heavy cream
3/4 cup (6 fl oz/180ml) whole milk
5 large egg yolks, lightly beaten
1 tsp pure vanilla extract
1 tbsp 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 300F (150C). Have ready six 1/2-cup (4 fl oz/125ml) 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 (I add the water once I 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.