Preheat oven to 350 degrees F.
Prepare a 9x13" pan with non-stick cooking spray, or line pan with foil and spray foil lightly.
In a large bowl combine flour, cinnamon, pumpkin pie spice, baking soda and salt.
In a separate bowl, use an electric mixer to combine the butter and sugars until smooth and creamy.
Mix in egg and vanilla until combined, followed with pumpkin. Mix until just combined. Slowly add in dry ingredients, mixing until just combined, do not over mix. If adding white chocolate chips or nuts, fold into mixture.
Pour into prepared pan and bake for approximately 32-38 minutes or until toothpick inserted into center comes out almost completely clean.
Remove from oven and allow to cool slightly.