Preheat the oven to 350F and line a 9×13 baking pan with aluminum foil or parchment paper.
In a large mixing bowl, whisk together melted butter and brown sugar. Stir in the peanut butter, flax egg, and vanilla extract until well combined. Stir in flour and salt, then fold in chocolate chips.
Transfer the blondie batter into the prepared baking pan and spread it out into an even layer.
Bake for 30-35 minutes, or until fully cooked through. Remove from the oven, let cool completely, then cut into 8 even bars.
Store blondies covered in an airtight container up to 3 days at room temperature or up to a week in the refrigerator.
Find the full blog post here: https://theurbenlife.com/2020/11/30/vegan-peanut-butter-blondies/