Line a 13x9x2-inch baking pan with foil, extending the foil over edges of pan. Coat foil with cooking spray; set pan aside.
In a 6-quart Dutch oven melt butter over medium-low heat. Stir in marshmallows just until melted. Remove from heat. Stir in pretzels, pumpkin seeds, dried apricots, and oats.
Using a spatula coated with cooking spray, press pretzel mixture firmly and evenly into the prepared baking pan. Drizzle with caramel topping; sprinkle with salt. Cool completely (about 1 hour). Using the edges of the foil, lift uncut bars out of pan. Cut into bars (see Tip).
Tip: Layer bars between sheets of waxed paper in an airtight container. Store at room temperature up to 3 days.