This is the recipe for the caramel sauce that goes on top of coffee panna cotta.
Put sugar and 1/4 cup water into a medium saucepan. Cook over medium heat, stirring occasionally, until sugar has dissolved. Continue to cook, without stirring, until syrup comes to a boil, washing down sides of pan with a wet pastry brush to prevent crystals from forming. Let syrup boil, swirling pan occasionally, until medium amber, about 20 minutes.
Reduce heat to low. Add 1/2 cup plus 2 tablespoons water and the vanilla seeds; cook, stirring constantly, until syrup is just thick enough to coat the back of the spoon. If it is too thin, cook 2 to 3 minutes more; if it is too thick, add more water, 1 tablespoon at a time. Pour though a fine sieve into a bowl. Let cool completely.