Tracy Kelly's Hot Fudge

1/2 C cocoa
1/3 C light Karo syrup
3/4 C sugar
2/3 C evaporated milk (half a can)
1/3 C butter
1 t. vanilla

Combine cocoa, syrup, sugar and milk in a saucepan. Bring to a boil whisking constantly.  Boil 1 + minute.  Remove from heat.  Add butter and vanilla.  (Seems to work out okay to cut back on the butter a little.  I've been adding a pinch of salt.)