In a medium saucepan, combine the unsalted butter, granulated sugar, whole milk, and unsweetened cocoa powder.

Place the saucepan over medium heat. Stir continuously with a spatula until the butter is melted and the sugar has dissolved completely.

Increase the heat to bring the mixture to a full, rolling boil. Once it reaches a rolling boil, stop stirring and allow it to boil for exactly 60 seconds. Use a timer for best results.

Immediately remove the saucepan from the heat to prevent overcooking.

Stir in the creamy peanut butter and vanilla extract into the hot mixture until everything is smooth and glossy.

Add the quick-cooking oats and salt to the saucepan. Stir until all the oats are thoroughly coated in the chocolate mixture.

Let the mixture cool in the saucepan at room temperature for about 10 minutes. Then, cover and place it in the refrigerator for 30-45 minutes, or until the mixture is firm enough to handle but still pliable.

Line a large baking sheet with parchment or wax paper. Place the powdered sugar in a shallow bowl or on a plate.

Use a small cookie scoop (about 1 tablespoon) to create evenly sized portions of the chilled chocolate-oat mixture.

Roll each portion between the palms of your hands to form a smooth, round ball.

Gently roll each ball in the powdered sugar until it is completely and generously coated. Shake off any excess.

Place the finished chocolate snowballs on the prepared baking sheet. Let them set at room temperature for about 30 minutes before serving or storing.