Combine sugar, butter, milk and cocoa in medium saucepan. Cook over medium heat, stirring constantly, until mixture comes to rolling boil; boil and stir 1 minute. Remove from heat.
Immediately add oats, peanut butter, peanuts and vanilla; stir to mix well. Quickly drop mixture by heaping teaspoons onto wax paper or foil. Cool completely. Store in cool, dry place. About 4 dozen.