Spread the salted caramel sauce evenly across a serving platter or board to create a smooth base layer.
Place the white chocolate chips in a microwave-safe bowl and heat in 20-second bursts, stirring between each, until fully melted and smooth.
Transfer the melted white chocolate to a piping bag or zip-top bag with a small corner snipped off, then pipe a spiderweb pattern over the caramel.
Melt the black candy melts in the same way as the white chocolate, then pipe small spider shapes onto the web or along the edge of the caramel.
Sprinkle the flaky sea salt evenly over the caramel surface.
Arrange the pretzel rods around the caramel and scatter the candy-coated chocolates in any open spaces on the board.