I ain't saying this is the best caramel sauce in the entire world. but it's certainly the best caramel sauce I've eaten in, oh, the last few years. As is so often the case with all things sweet, I discovered it through Nigella Lawson, who cites it as an excellent topping for coffee meringues with whipped cream. I made a batch to see if the meringues might suit for Christmas dinner (they might) and found myself with a ton of leftover sauce after I'd prepared my test meringue.
This proved no hardship. The sauce is excellent as a topping for, well, pretty well everything you'd normally top with caramel: ice cream, cake, the bowl of a large spoon, etc. Blended with milk or cream and topped with fresh brewed coffee, it also makes a painfully delicious caramel latte.
I have to share it with you. The sauce leaves me no choice.
1 tablespoon butter
1/4 cup golden syrup
2 tablespoons brown sugar
1/4 cup heavy cream
2 teaspoons Frangelico or another hazelnut liqueur (optional, but highly recommended)
I strongly encourage you to use golden syrup over corn syrup, if at all possible. Golden syrup is made from sugar cane, while corn syrup's origins are obvious. The syrup contributes so much flavour to the sauce that you really don't want to cut corners here. I know the Americans among you don't always have easy access to golden syrup, though, so if you've gotta use corn syrup, you've gotta use corn syrup.
Put the butter, golden syrup, and brown sugar in a small pot over low heat. Don't stir them; just swirl the pan now and again so they blend together as they melt.
Bring the sweet stuff to a boil and leave it entirely alone for two minutes. Immediately remove it from the heat and whisk in the cream and Frangelico (if using).
I'll warn you, the freshly-made syrup is alarming. It looks thin as water when it first comes off the heat, but believe me when I say it will thicken up a bit as it cools. Even then, it'll remain the perfect consistency for pouring.
I trust you can figure out the caramel-as-topping angle on your own. If you'd like to use the stuff to make a latte, blend two tablespoons of it with a roughly equal amount of heavy cream. Top the mixture with hot coffee (or brew the coffee directly into it, if you have a Keurig or similar), give it a wee stir, and enjoy. I like it without sugar, myself, though I should note that it's rather less sweet than an equivalent drink from a place like Tim Horton's.