Measure out the peanut butter and oats; set aside. Lay out 2 silicone pan liners or sheets of parchment paper. (You can place them inside cookie sheets.)
Combine the sugar, butter, chocolate chips, and milk in a large saucepan or pot. Cook over medium heat just until the chocolate chips and butter are melted. It might start to simmer around the edges, but it doesn't need to boil.
Remove from the heat. Quickly stir the vanilla, salt, and peanut butter into the chocolate mixture. Then stir in the oats.
Quickly scoop the mixture with a tablespoon-sized cookie scoop onto the silicone liners. (Work quickly - they start to set up pretty fast!)
Let the cookies sit for 15-20 minutes, or until cooled and set.
Notes
-Make sure you have your ingredients ready to add to the chocolate mixture. You need to work quickly so it doesn't set up before you have all the cookies scooped.