In a small heavy saucepan melt sugar over medium-high heat until sugar begins to melt, shaking pan often. (Do not stir.) Reduce heat; cook about 5 minutes more or until sugar is melted and golden. Stir as necessary after sugar begins to melt (only when mixture bubbles). Remove from heat.
Carefully pour in whipping cream. Add butter. Return to heat; cook and stir for 1 to 2 minutes more or until smooth. Stir in pecans; cool. Makes about 1 cup (12 servings).