Bake brownies according to directions on box. Crumble brownies and set aside.
Beat eggs. In a large saucepan, combine sugar, corn syrup, melted butter and eggs. Stir in salt, vanilla and chopped pecans. Bring to a boil over medium heat. Reduce heat, and simmer for 10 minutes, stirring frequently. Cool.
In a trifle dish, layer brownie crumbs, pecan mixture, whipped topping, caramel and toasted whole pecans; repeat as desired. Chill 2 hours before serving.