1. Preheat oven to 350°F.2. Add the peanut butter and melted butter to a stand mixer fitted with a paddle attachment, beat on medium speed.3. Add the brown and white sugar, mix until well combined. Add the eggs, beer, and vanilla one at a time, beating well between additions.4. Stir in the salt, flour and half of the chocolate chips.5. Spray an 8x8 baking dish with cooking spray (or line with parchment paper) pour the batter into the pan in an even layer.6. Top with remaining chocolate chips and pretzels.7. Bake until the edges have turned golden brown, about 35-40 minutes.8. Allow to cool before cutting.