Pumpkin Chocolate Chip Cookies

In a medium size bowl, combine flour, oats, baking soda, pumpkin pie spice and salt. Stir to combine.
In a mixing bowl, beat butter and sugars until light and fluffy, approximately 2-3 minutes. Add pumpkin, egg and vanilla extract and beat to combine.
Add dry mixture to wet mixture and mix by hand until combined, do not overmix. Fold in chocolate chips, and nuts if using. Cover dough and place into refrigerator for at least 30 minutes, and up to two hours*.
When ready to bake, preheat oven to 350 degrees F. Prepare 3 baking sheets with parchment paper or a silicone baking mat. Using a large cookie scoop, drop dough onto baking sheet in approximatley 3 tbsp portions.
Bake each sheet (one at a time) for 15-20 minutes or until cookies are firm and brown on the edges. Cool on baking sheets, on wire cooling rack, for 5 minutes, then using a spatula, gently transfer cookies from baking sheet directly onto the wire cooling rack, and allow to cool completely. Repeat with remaining cookie dough. Store loosely covered.