Line a baking sheet with wax paper or parchment.
Bring the sugar, milk, butter and cocoa to a boil in a medium pan over medium heat, stirring occasionally, then let boil for 1 minute.
Remove from the heat. Add the oats, peanut butter, vanilla and salt, and stir to combine.
Use a teaspoon or spoon to scoop the mixture onto the prepared wax paper, and let sit at room temperature until cooled and hardened, about 30 minutes.
