In a medium bowl, whisk together the melted butter, brown sugar, and granulated sugar until smooth and no brown sugar lumps remain.
Add the vanilla extract and blotted pumpkin puree; whisk until fully combined. Set aside.
In a large bowl, whisk together the flour, salt, baking powder, baking soda, ground cinnamon, and pumpkin pie spice.
Pour the wet ingredients into the dry ingredients and stir with a rubber spatula or large spoon until a soft dough forms.
If using, fold in 1/2 cup white chocolate chips. (They may not fully stick due to the melted butter—just do your best to combine.)
Cover the dough and chill in the refrigerator for at least 30 minutes or up to 3 days.
Once chilled, preheat the oven to 350°F (177°C) and line two large baking sheets with parchment paper or silicone baking mats.
Scoop about 1.5 tablespoons of dough per cookie and roll into balls.
Mix the cinnamon-sugar coating in a small bowl, then roll each dough ball generously in the coating.
Place cookies about 3 inches apart on the prepared baking sheets.
Slightly flatten each dough ball using the back of a spoon or the bottom of a measuring cup.
Bake for 11–12 minutes, or until edges are set and centers appear soft.
If cookies haven’t spread much, gently press them down with the back of a spoon immediately after baking.
Let cookies cool on the baking sheet for at least 10 minutes before transferring them to a wire rack to cool completely.
Once the cookies have cooled down serve them.