Preheat oven to 350 degrees F. Line a 13x9x2-inch baking pan with heavy foil, extending foil over the edges of the pan; set pan aside. In a large bowl, beat butter with an electric mixer on medium to high speed for 30 seconds. Add brown sugar, egg yolks, and vanilla. Beat until combined, scraping bowl occasionally. In a small bowl, combine flour, pretzels, baking powder, and baking soda. Beat in as much of the flour mixture as you can with the mixer. Using a wooden spoon, stir in any remaining flour mixture. Press mixture into the bottom of the prepared pan.

Bake in the preheated oven for 12 to 14 minutes or until lightly browned. Meanwhile, in a medium microwave-safe bowl, combine marshmallow creme and peanut butter. Microwave on 100 percent (high) power for 1 minute or until softened and slightly melted, stopping to stir after 30 seconds. Stir in powdered sugar. Spread mixture over crust. Sprinkle with salted peanuts.

In a heavy large saucepan, combine unwrapped caramels and milk. Cook and stir over medium-low heat until melted and smooth. Pour caramel mixture evenly over peanut layer. Cool in pan on wire rack. Using the foil, lift the uncut bars out of the pan. Cut into bars. Makes 48 bars.

Place bars in a single layer in an airtight container; cover. Store in the refrigerator for up to 1 week.