Allow butter to soften to room temperature for ~1 hour.
Preheat oven to 350°F (180°C). Line 2 large baking sheets with parchment & spray with cooking spray.
In a large bowl, cream together softened butter, white sugar, and brown sugar with a hand mixer on medium speed, until fluffy & combined.
Then add pumpkin puree, cinnamon, pumpkin pie spice, and vanilla and beat with the mixer until integrated.
Separately, whisk together flour, baking soda, and salt.
Add dry mixture into the wet mixture in 2-3 batches, beating with a hand mixer as you go to form a dough.
Scoop ~1 Tbsp dough and roll into 1-inch balls with your hands. (I used a #60 cookie scoop.) Transfer to a prepared baking sheet and flatten each ball slightly into a disk.
Bake pumpkin cookies 12-14 minutes, until starting to brown at the edges.
Allow to cool for 10 minutes before transferring to a wire rack. Once transferred, drizzle pumpkin cookies with icing while they’re still warm!
To make a quick cookie icing: Whisk together 1½ cups powdered sugar, 1-2 Tbsp milk of choice, and ¼ tsp vanilla extract (optional). Use a spoon to drizzle icing over warm cookies & allow to set.
Storage: Keep unfrosted or frosted pumpkin cookies in an airtight container at room temperature for up to 7 days.