COMBINE syrup, sweetened condensed milk and salt in heavy saucepan over medium heat. Cook and stir 12 to 15 minutes or until slightly thickened.
REMOVE from heat; stir in vanilla. Serve warm with dippers.
COMBINE syrup, sweetened condensed milk and salt in 1-quart glass measure. Cook on HIGH (100% power) 3 1/2 to 4 minutes, stirring after 2 minutes. Stir in vanilla.
Can be served warm or cold over ice cream. Can be made several weeks ahead.