Line a large baking sheet with parchment paper or a silicone baking mat to prevent sticking and make cleanup easy.
In a small bowl, stir together the creamy peanut butter, powdered sugar, vanilla extract, and fine sea salt until smooth, thick, and spreadable. The texture should be like slightly stiff frosting. If it seems too loose, add a little more powdered sugar, 1 teaspoon at a time.
1/2 cup creamy peanut butter, 2 tablespoons powdered sugar, 1 teaspoon vanilla extract, 1/8 teaspoon fine sea salt
Spread half of the pretzels in a single layer on the prepared baking sheet. These will be the bottoms of the sandwiches.
2 cups small pretzel twists or square pretzels
Using a small spoon or a piping bag (you can use a zip-top bag with the corner snipped), place about 1/2 teaspoon of the peanut butter mixture onto each pretzel, leaving a small border around the edges so it doesn’t squeeze out too much when topped.
1/2 cup creamy peanut butter, 2 tablespoons powdered sugar, 1 teaspoon vanilla extract, 1/8 teaspoon fine sea salt
Gently press a second pretzel on top of each peanut butter mound to form little sandwiches. Arrange them on the baking sheet, then place the sheet in the freezer for 10–15 minutes to firm up the filling so they’re easier to dip.
2 cups small pretzel twists or square pretzels
In a microwave-safe bowl, combine the semi-sweet chocolate chips and coconut oil or shortening. Microwave on 50% power in 30-second bursts, stirring between each, until the chocolate is mostly melted. Then stir until completely smooth. Alternatively, melt in a heatproof bowl set over a pot of gently simmering water, making sure the bowl does not touch the water.
1 1/2 cups semi-sweet chocolate chips, 1 tablespoon coconut oil or vegetable shortening
Place the bowl of melted chocolate next to the chilled pretzel sandwiches and keep the parchment-lined baking sheet nearby for the coated pretzels. Have a fork or dipping tool ready. If the chocolate begins to thicken as you work, warm it again for 10–15 seconds at 50% power.
Working with a few sandwiches at a time, carefully lower each pretzel sandwich into the melted chocolate. Use a fork to flip and coat it completely. Lift it out, gently tap the fork on the edge of the bowl to remove excess chocolate, then slide the coated pretzel back onto the lined baking sheet.
2 cups small pretzel twists or square pretzels, 1 1/2 cups semi-sweet chocolate chips, 1 tablespoon coconut oil or vegetable shortening
While the chocolate is still wet, immediately sprinkle the tops with flaky sea salt, sprinkles, or crushed peanuts, as desired. Repeat with all pretzel sandwiches, grouping different toppings if you like.
flaky sea salt, sprinkles, or crushed peanuts
Transfer the baking sheet to the refrigerator for 20–30 minutes, or to the freezer for 10–15 minutes, until the chocolate coating is fully set, matte, and no longer tacky to the touch.
Once the chocolate is firm, lift the pretzels off the parchment and transfer them to an airtight container. Enjoy chilled or at room temperature. Store at room temperature up to 3 days (if cool and dry), in the refrigerator for 1–2 weeks, or freeze for up to 2 months.