1] Drizzle 2 Tbsp. of the caramel topping on the bottom of the crust and sprinkle with 3 Tbls. of the pecans. Set aside.
2] Whisk the milk and pudding mix in a bowl, beating constantly until well blended, about 2 minutes. Add the pumpkin and pie spice, beating with whisk until blended. With a rubber spatula, gently fold half of the whipped topping into the pumpkin mixture just until blended. Repeat with remaining half of whipped topping.
3] Spread the filling in the crust and refrigerate until set, at least 2 hours or overnight. Sprinkle the top with the remaining 1 Tbsp. of pecans; then drizzle with the remaining 1 Tbsp. of caramel topping. Serve at once.