Spray a 9x13" baking pan with PAM or Baker's Joy. Set aside.
For filling, whisk together softened cream cheese, sugar and egg. Mix with a hand mixer until well-blended and smooth. Set aside.
For batter, combine pumpkin, sugar, egg and oil in medium mixing bowl. Mix well.
Stir in flour, pumpkin pie spice, baking powder, baking soda, & salt. Mix well to combine.
Pour batter into prepared baking dish, and spread to cover bottom of pan.
Drizzle the cream cheese mixture over the batter. Cut through the batter with a knife or spatula, to make a marbled effect w/ the cream cheese mixture. Do this a second time, going in the opposite direction [i.e., if you go side to side the first time, go up and down the second time]. When doing the marbling, be cautious and don't let your knife drag or touch the bottom of the baking dish.
Sprinkle with the chopped pecans.
Bake 25 - 28 minutes, or until a cake tester comes out clean.
Cool the entire pan of bars, then cut into squares.