Preheat oven to 350 degrees. Spray 8x8 square dish with nonstick cooking spray and set aside.
In a large bowl, cream butter and sugar together. Stir in egg, vanilla and pumpkin. Pour in all dry ingredients and stir until just combined. Stir in chocolate chips.
Spread dough evenly into prepared baking dish. Bake 15-20 minutes or until toothpick comes out clean after being inserted. {My oven is hotter than the sun, so mine was done at 15 minutes. Keep an eye on yours!} Remove from oven, cool 5-10 minutes, cut into bars and serve warm. Or wait and serve at room temperature. But of course I can never wait.