Beat peanut butter and butter until smooth. Mix in powdered sugar, vanilla and salt until a firm dough forms.
Divide into 30 balls and set on a parchment-lined tray. Refrigerate for 30 minutes, additional to the listed active time, until firm enough to lift cleanly.
Melt chocolate and coconut oil in a microwave-safe bowl at 50% power in 30-second bursts, stirring between bursts, for 2 to 3 minutes total. Let cool for 2 minutes so it is warm rather than hot.
Insert a toothpick into each peanut butter ball and dip most of it in chocolate, leaving a small bare circle at the top. Let excess drip off, set back on the tray and remove the toothpick.
Smooth the top holes gently with the back of a small spoon if desired. Refrigerate for 20 minutes until the chocolate sets, then store chilled in a covered container.