Line two baking sheets with parchment paper. Set aside.
In a medium saucepan, combine sugar, butter, milk, and cocoa powder. Bring it to a boil over medium heat. Once it is at a rolling boil, boil for 1 minute.
Remove from the heat and whisk in the peanut butter, vanilla, and salt until smooth. Stir in oats. Drop by spoonfuls or use a cookie scoop to drop the oat mixture on the prepared baking sheet.
Refrigerate for at least 30 minutes or until cookies are set.
