This is a recipe there shouldn't be much to say about--it's a regular old crème anglaise or custard sauce with brown sugar instead of white sugar.
But custard sauce is a tricky thing to get just right. All fears of curdling aside, what's the right proportion of egg yolks to milk? Milk or cream? I have a French cookbook that calls for 6 egg yolks for a liter of milk; I saw an Australian recipe calling for 10. Most recipes have some milk and some cream. A lot of people use custard powder or vanilla pudding mix to make custard sauce.
Maida's recipe here takes a nice middle path--4 egg yolks, 1 cup milk, 1 cup cream. No other thickener. And for once, she's conservative with the sugar--where many recipes have you use 1/2 cup of sugar for 2 cups of liquid, she's got only 1/3 cup.
So a decent consistency, not too sweet--but not very exciting, either. When I read "butterscotch", I think of a real "pow!" of toffee flavor--butter and brown sugar and even a bit of booze. I think I've been conditioned by recipes like this and this.
Still, it's a custard sauce, which is almost always a good thing.
It was very nice with the broiled peppered pears, and while we were eating it, Claire suggested it might taste good as ice cream. Why not? We eat a lot more custard sauce now than we used to, since mass-produced European ice cream is nasty. Since we were about to leave for vacation, I went ahead and put it in the freezer (no room for the ice cream maker in that tiny compartment), where it froze into a hard clump. Still, when thawed a bit and served with apple crumble, it was a real treat.
So here's the recipe. If you're looking for a nice basic custard sauce with a bit of a caramel-y undertone, you won't be disappointed.
Butterscotch Custard Sauce
1 c. (8 oz.) milk
1 c. (8 oz.) heavy cream (I don't see why you couldn't use 2 cups of half-and-half, if you have it)
1/3 c. (2.3 oz.) brown sugar
4 egg yolks
1 t. vanilla (I used vanilla sugar for some of the brown sugar)
In a small pan over medium heat, or in a glass measuring cup in the microwave, heat the milk and cream with the sugar and salt (and if you have a used vanilla bean, throw that in as well) until it is steaming and a skin is beginning to form. Meanwhile, in a somewhat larger saucepan with a heavy bottom, whisk the yolks just to mix. Slowly whisk in the milk/cream mixture. Place over medium-low heat and cook, stirring and scraping with a heatproof rubber scraper, until the mixture thickens slightly and coats the back of a spoon (180 on a thermometer). Pour through a strainer into a bowl or back into that glass measuring cup you used earlier. Stir in the vanilla. Cool to room temperature, stirring it when you think about it. Then chill and serve very cold--Maida even suggests freezing this for a bit. Serve with anything--especially fruit or chocolate desserts--that needs a bit of a cool, creamy lift.