In a saucepan, melt butter, then add sugar, milk and vanilla. Bring to a boil stirring constantly. Once at full boil, allow to boil for 3 minutes without stirring.

Remove from heat and quickly stir in cocoa and oats. Very quickly drop by teaspoonfuls onto a parchment lined baking sheet. Mixture will setup quickly, so get all the cookies dropped as quick as you can.

Allow to cool and dry completely. Do not refrigerate, store in an air tight container