In a large bowl, combine butter with peanut butter and powdered sugar until a thick dough forms. Evenly divide the peanut butter mixture over half of the pretzels.
Sandwich with the remaining half of pretzels. Set the pretzel bites onto a plate and refrigerate for at least 20 minutes.
Place the chocolate chips into a microwave-safe bowl, and heat in the microwave in 30-second intervals, stirring until they are fully melted and smooth. Place the sprinkles into a shallow dish.
Dip half of each pretzel bite into the melted chocolate, dip into the sprinkles. Set onto a plate, and refrigerate for another 20 minutes.
