In a large heavy saucepan, cook butter over medium heat for 4-6 minutes or until golden brown. Stir in sugar and corn syrup; cook and stir for 2 minutes or until sugar is dissolved. Remove from the heat; gradually stir in cream.
Bring to a boil. Reduce heat to medium. Cook until sauce begins to thicken. Remove from the heat. Stir in pecans and vanilla. Serve warm over ice cream.