Preheat oven to 350 degrees. Grease an 8x8 baking pan.
In a medium bowl, combine flour, baking soda, and salt.
In a separate bowl combine butter, eggs, brown sugar, sugar, and vanilla. Use a handmixer to completely combine.
Add flour in 3 batches, scraping the side of the bowl after each addition. Once all of the flour is combined, use a spatula to fold in peanut butter chips and pretzels, reserving some for the top.
Transfer batter to prepared baking pan.
Bake for 40 minutes, or until a toothpick inserted into the center of the pan comes out clean.
Top bars with remaining peanut butter chips and pretzels.
Allow to cool before slicing into squares and devouring!