Preheat the oven to 375°F. Line 2 baking sheets with parchment paper.
To make the dough: In the bowl of a stand mixer fitted with the paddle attachment, add the butter, brown sugar, cane sugar, and vanilla extract. Mix on low until combined and there are no chunks of butter.
Add the molasses and mix on low until combined.
Add the pumpkin to the butter mixture.
Next add the dry ingredients: all purpose flour, baking soda, and salt in that order.
Using your hands (or a cookie scoop) form the dough into 12 balls and place on the lined baking sheet, spacing evenly apart. You'll have 6 cookies per cookie sheet.
Bake for 15 to 17 minutes or the center looks set and cracked until the bottoms are golden brown. Allow to cool completely on the baking sheets.
To make the glaze: In a medium bowl add the powdered sugar and milk and whisk until a smooth glaze forms.
Spread the glaze over the tops of the cookies, I just use a butter knife for this.
Store in an airtight container for up to 7 days, or you can also freeze for longer.