Spray 6 jumbo muffin tins with crisco no stick cooking spray. Prepare box of brownie mix as directed on package, dividing batter among prepared muffin tins. Bake 325 for 42-45 minutes; cool.
Pour hot fudge topping into 1 quart resealable freezer bag; microwave 20 seconds and knead. Snip small corner off bag.
For each sundae, squeeze caramel sundae syrup onto center of dessert plate; place brownie in center. Coat one end of a few nuts from jar of pecans in syrup with hot fudge topping; place around base of brownie.
Top brownie with scoop of vanilla ice cream. Drizzle generously with caramel and hot fudge topping, and place 2 nuts on top. Serve immediately.