Butterscotch Sauce

In a medium heavy-bottomed saucepan, combine the brown sugar, butter, corn syrup, and water over medium heat. Stir gently until the butter melts and the sugar begins to dissolve.

Bring the mixture to a gentle boil, stirring constantly to prevent scorching on the bottom of the pan. Reduce heat slightly to maintain a steady, controlled simmer.

In a small bowl, whisk the egg yolk until smooth and slightly pale. Temper the yolk by slowly adding a few tablespoons of the hot sugar mixture while whisking vigorously to prevent curdling.

Slowly pour the tempered egg yolk mixture back into the saucepan while stirring continuously. This step enriches the sauce and gives it a velvety, luxurious texture.

Continue cooking the sauce over medium-low heat, stirring constantly, until it thickens enough to coat the back of a spoon and achieves a deep golden-brown color.

Remove the saucepan from the heat and allow the sauce to cool in the pan for a few minutes, during which it will continue to thicken slightly.

Transfer the butterscotch sauce to a clean heatproof jar or serving vessel. Serve warm over desserts or store in the refrigerator in a sealed container for up to two weeks.