This traditional sauce, made from caramelized sugar and milk, can be served by itself or over ice cream or fruit, as we did in our Bunuelos with Vanilla Ice Cream and Cactus Berries.
Combine sugar, salt, lemon juice, and 1 tablespoon water in wide, heavy-bottomed saucepan over medium-low heat. Cover saucepan and cook, checking occasionally until sugar melts and turns amber, 10 to 12 minutes. Do not overcook or sugar will burn.
Remove from heat and slowly whisk in goat's milk. Let cool completely. Drizzle cajeta sauce over ice cream and serve, or store covered in refrigerator up to 1 week.