Preheat oven to 400° Lightly grease or coat with non stick spray a 9x13 inch pan.
In the large bowl of a hand or stand mixer combine butter and sugar, mix until smooth. Add egg, vanilla, and pumpkin - mixing well to combine thoroughly.
In a separate bowl whisk flour, pumpkin pie spice, and cinnamon. Incorporate flour a little at a time to pumpkin mixture until fully mixed. Fold in walnuts, butterscotch and white chocolate chips.
Pour batter into baking pan and smooth with spatula. Bake for 400-45 minutes until top is golden and center is done (insert toothpick, if it comes out clean-its done).
Allow to completely cool, cut into squares, and store in an airtight container for 4-6 days.