Whisk the melted butter, brown sugar, and granulated sugar together in a medium bowl until no brown sugar lumps remain. Whisk in the vanilla and blotted pumpkin until smooth. Set aside.
Whisk the flour, salt, baking powder, baking soda, cinnamon, and pumpkin pie spice together in a large bowl. Pour the wet ingredients into the dry ingredients and mix together with a large spoon or rubber spatula. The dough will be very soft. Fold in ½ cup white chocolate chips, if using.
Cover the dough and chill for 30 minutes or up to 3 days. Chilling the dough is a must for this recipe.
Remove dough from the refrigerator. Preheat oven to 350°F (177°C). Line two large baking sheets with parchment paper or silicone baking mats.
Scoop the dough, about 1.5 Tablespoons of dough per cookie, and roll each into balls. Mix the coating ingredients together, and then roll each cookie dough ball generously in the cinnamon-sugar coating. Arrange cookie dough balls 3 inches apart on the prepared baking sheets. Using the back of a spoon or the bottom of a cup/measuring cup, slightly flatten the tops of the dough balls.
Bake for 11–12 minutes or until the edges appear set. The cookies will look very soft in the center. Remove from the oven. If you find that your cookies didn’t spread much at all, flatten them out gently with the back of a spoon when you take them out of the oven. If desired, press a few white chocolate chips into the tops of the warm cookies.
Cool cookies on the baking sheets for at least 10 minutes before transferring to a wire rack to cool completely. The longer the cookies cool, the better they taste!
