Preheat oven to 350 degrees F.
Mix the flour, salt and baking soda in a bowl and set aside. In another bowl, whisk the melted butter, peanut butter and sugars until they are combined.
Add the egg, egg yolk, and vanilla extract and stir until mixed. Gradually add flour and mix until a dough forms – it will look crumbly at first, but it will come together. I even used my hands to help at one point. As it’s coming together, fold in the crushed pretzels and chocolate chips. Use you hands and form dough into 1-inch balls; you may need to squish it together somewhat to keep the ball together. Place on a baking sheet about 2 inches apart.
Bake for 8-10 minutes, or until slightly golden and set. Let cool for 10-15 minutes before eating!