Easy (but really good) Hot Fudge Sauce

(adapted from a recipe on COOKS.COM)

1/2 c. butter

1/2 c. cocoa

1 1/2 c. sugar

1 1/2 c. cream

2 t. vanilla

While stirring, heat butter and cocoa in a medium saucepan until melted. Remove from heat and stir in sugar until it is evenly grainy and you can't see any white. Now stir in cream. Return to heat, and heat to boiling, while stirring frequently. Let it boil 3-5 minutes continuously stirring. Let cool. Serve over ice cream. Can store in jar in refrigerator and briefly warm up in microwave before using.