Cook bacon in a large skillet over medium-high heat 10 minutes or until crisp; remove bacon, and drain on paper towels. Coarsely chop bacon. Pour popped popcorn into a large bowl. Toss with bacon, Parmesan cheese, melted butter, and buttermilk Ranch dressing mix. Sprinkle with freshly ground pepper, and serve immediately.
Note: For testing purposes only, we used Orville Redenbacher's Natural Simply Salted 50% Less Fat Gourmet Popping Corn.