Preheat your oven to 350°F (175°C). In a mixing bowl, combine crushed pretzels, melted butter, and brown sugar. Press this mixture into the bottom of a 9-inch pie dish. Bake for about 10 minutes until golden brown.

While the crust cools, whisk together peanut butter, powdered sugar, and cream cheese until smooth. Add vanilla extract and a pinch of sea salt if desired.

Gently fold in whipped cream into the peanut butter mixture. Pour this filling into the cooled pretzel crust.

Cover the pie with plastic wrap and refrigerate for at least 4 hours or overnight.

Slice and serve the pie, optionally sprinkling crushed pretzels on top for added crunch.