2/3 c. unsweetened cocoa
6 tbsp. butter, cut into sm. pieces
1/2 c. hot tap water
1 c. sugar
2 tbsp. light corn syrup
2 tsp. vanilla

Combine cocoa, butter, and water in a microwave-safe bowl or saucepan and microwave 1 to 1-1/2 minutes on 70 percent power (medium-high) or until butter is melted. Stir in sugar and corn syrup and microwave 8 to 10 minutes on 70 percent power, stirring twice or until sauce is simmering and starting to thicken. Let cool 5 minutes and then stir in vanilla. Serve warm.

Note: Sauce thickens more as it cools.