1 c. sugar
1 1/2 c. hot water
2 tbsp. instant coffee powder
3 tbsp. cornstarch
2 tbsp. cold water
3 tbsp. butter
1/4 c. rum
1 pt. coffee ice cream
1 pt. vanilla ice cream

In a large skillet over medium heat, melt sugar until golden, stirring constantly after it begins to melt. Combine hot water with instant coffee powder. Slowly and carefully stir it into melted sugar, then cook, stirring until sugar is completely dissolved in hot coffee.

Remove sauce from heat. Mix cornstarch with cold water until smooth. Stir into sauce. Return to heat; continue cooking, while stirring, until sauce is thickened and smooth. Remove from heat; add butter and rum; stir until butter is melted. Refrigerate sauce, covered, until just before serving.

About 5 minutes before serving, reheat sauce. Into each of 6 sherbet dishes, spoon 1 scoop of coffee and 1 scoop of vanilla ice cream. Then pour hot sauce over each sundae. Serve immediately. This is definitely worth the work!