No-bake layered bars with a chocolate base, a single layer of pretzels, a peanut butter powdered-sugar filling, and a chocolate top — inspired by Chubby Hubby.
Line a 9x13-inch pan with parchment paper, leaving an overhang on two sides for easy removal.
Put half of the finely chopped semisweet chocolate (about 8 ounces) in a medium microwave-safe bowl. Microwave at 50% power in 30-second increments, stirring after each increment, until completely melted and smooth.
Pour the melted chocolate into the prepared pan and use an offset spatula or the back of a spoon to spread it into an even layer covering the bottom.
Arrange the pretzel sticks in a single, even layer over the chocolate, spacing them so they sit mostly flat. Press gently so the pretzels make contact with the chocolate but are not submerged. Refrigerate the pan until the chocolate is set, about 10–15 minutes.
In a medium bowl whisk together the melted unsalted butter (4 tablespoons) and the creamy peanut butter (1 cup) until combined. Whisk in the powdered sugar (1 cup) until the mixture is smooth and spreadable.
Spread the peanut butter mixture in an even layer over the set pretzel layer, smoothing the top with a spatula.
Melt the remaining half of the finely chopped chocolate using the same microwave method (50% power, 30-second increments, stirring until smooth). Let the melted chocolate sit 30–60 seconds to cool slightly, then pour it over the peanut butter layer and spread into an even top layer.
Refrigerate the pan until the top chocolate is fully set, about 30 minutes. Use the parchment overhang to lift the slab from the pan and transfer to a cutting board.
Cut into bars and serve. Store leftovers in an airtight container in the refrigerator for up to 2 weeks.