Mix peanut butter, sifted powdered sugar, softened butter, vanilla, and salt in a bowl until smooth and thick. If too soft, refrigerate 15 minutes before using.
Lay half the pretzels on a parchment-lined baking sheet. Scoop about 1 teaspoon of filling onto the center of each. Press a second pretzel on top until filling spreads to the edges without overflowing. Refrigerate assembled bites for 20–30 minutes until firm.
Combine chocolate chips and coconut oil in a microwave-safe bowl. Microwave in 30-second intervals, stirring between each, until fully melted and smooth. Do not overheat.
Hold each chilled bite by one edge and dip halfway into the melted chocolate. Let excess drip off and place back on the parchment-lined tray. Sprinkle flaky salt over each immediately before the chocolate sets.
Refrigerate the dipped bites for 15–20 minutes until chocolate is fully set and firm. Serve cold or at room temperature.
