Line 8x8-inch pan with parchment paper. The paper should overhang the edges of the pan, this makes it easy to remove the bars from the pan.

In bowl of stand mixer fitted with paddle attachment, cream together peanut butter and cream cheese on medium speed. Stop mixer. Scrape down bottom and sides of the bowl. Add powdered sugar. Mix until blended. Add the crushed corn chex. Mix to combine. Dough will be stiff. Add melted butter. Blend to combine.

Press dough evenly into prepared baking pan. Spread melted chocolate evenly over the top of the pans. Press mini-pretzels into the melted chocolate. If the pretzels aren't coated with a lot of salt (gluten-free pretzels are usually light on the salt), sprinkle a little kosher salt evenly over the bars. The salty-sweet mix really makes these bars yummy.

Chill bars for 45 minutes. Remove the bars from the refrigerator and allow to come to room temperature, about 45 minutes. Lift bars out of the pan using the parchment paper. Cut into pieces with a sharp knife. Serve. Store leftover bars in the refrigerator.

Note: Cutting the bars while cold causes the chocolate to break apart. It's important to allow them to come to room temperate before cutting.