Preheat oven to 350 degrees F. and line a 9 x 13-inch baking dish with parchment paper.
Prepare brownie mix according to package direction and pour into prepared baking dish. Top evenly with pretzels and peanuts. Bake for 30 minutes or until baked through. Remove and let cool completely.
Cut brownies into squares and top each square with a few pieces of popped popcorn. Drizzle tops with melted chocolate and let set up for a few minutes. Serve room temperature.