Mix sugar, milk, butter and cocoa in a large pan. Bring to a boil. Start timing when mixture reaches a full roiling boil and boil for only 1 1/2 minutes. This is the trick to successful cookies. If you boil too long the cookies will be dry and crumbly- not long enough cookies won't form properly.

Remove from heat and add peanut butter, oats and vanilla. Stir well. Drop by teaspoons onto wax paper. Let cool until hardened.

~This is one of my all time favorites from my childhood~