How to Make It
Preheat oven to 350°F. Spread oats in an even layer on a rimmed baking sheet. Bake in preheated oven until oats turn light brown and have a strong, nutty aroma, 8 to 10 minutes, stirring once after 5 minutes. Remove from oven.
Line 3 baking sheets with parchment paper. Whisk together granulated sugar, butter, milk, and brown sugar in a medium saucepan over medium until combined. Let mixture come to a boil; boil, undisturbed, 1 minute. Remove from heat; stir in peanut butter, vanilla, and salt until combined. Stir in oats. Let stand 5 minutes.
Drop tablespoonfuls of oat mixture onto prepared baking sheets (you will have about 54 cookies). Using your fingers, make a hole in the center of each cookie (to look like a wreath). Decorate with chocolate pieces. Let cookies cool until set, about 30 minutes.