Combine in saucepan 1 cup light brown sugar, firmly packed, 1/8 teaspoon salt, 2 tablespoons butter and 1/3 cup milk. Cook, stirring until sugar is dissolved. Then cook without stirring until mixture forms a soft ball when dropped into cold water. Cool to lukewarm. Put into mixer bowl and beat on No. 10 speed until it begins to thicken. Add 1 teaspoon vanilla and 1 tablespoon cream. Continue beating until spreading consistency.