Preheat the oven to 350 degrees.

Spray a 9 x 13 baking dish with cooking spray.

In a medium bowl combine the flour, pumpkin pie spice, baking powder, and salt. Set aside.

In a large bowl cream together the butter, sugar, and brown sugar. Ad din the egg and mix well. Stir in the vanilla.

Add the pumpkin puree and mix until combined. Your batter may look curdled but that is normal.

Slowly add the dry ingredients to the wet ingredients and mix well. Fold in the white chocolate chips.

Spread the batter into the prepared pan and bake for 35-40 minutes or until a toothpick inserted into the center comes out clean.

Remove from oven and cool completely.

Cut into 24 squares and enjoy!