Preheat oven to 325 degrees and spray an 8x8 baking pan with nonstick cooking spray. In a large mixing bowl, using an electric hand mixer, blend the eggs and oil until fully incorporated. Slowly add the brownie mix and water, then blend until a thick batter forms. Pour batter into prepared pan and bake 18-20 minutes or until a toothpick inserted in the center comes out clean. Cool completely.
In a sauce pan over medium heat, melt together the butter, brown sugar, heavy cream and salt. Whisk until sugar is completely dissolved and the mixture begins to bubble. Turn the heat down to medium - low and simmer the caramel sauce 5 minutes, stirring frequently. Remove from heat and whisk in the vanilla, then place sauce pan in the freezer to thicken, about 5 minutes.
Remove the cooled brownies from the pan and crumble into small pieces with your hands. Pour 10 cups of popcorn into a large bowl, then drizzle the caramel sauce onto the popcorn and toss with a rubber spatula until the popcorn is evenly coated in the caramel. Reserve one cup of brownie crumbs, then sprinkle the rest of the crumbs and chopped pecans onto the popcorn and toss again until the popcorn is evenly coated.
Spread popcorn in one layer onto 2 sheet pans lined with parchment paper. Bake at 350 degrees for about 10-12 minutes. Remove brownie corn from oven, sprinkle remaining crumbs on top and toss gently. Allow to cool completely, then break up the large pieces with your hands and enjoy!