Preheat oven to 375. Brown the butter: Melt the butter in a saucepan over medium heat, stirring frequently, until it foams and the milk solids turn golden brown and smell nutty, about 5–7 minutes.
In a bowl whisk the all-purpose flour, cream of tartar, baking soda, cinnamon, salt, nutmeg and ginger. Set aside.
In a large bowl combine the browned butter, granulated sugar and brown sugar.
Whisk the pumpkin puree, egg yolks and vanilla extract and then add it into the butter sugar mixture.
Add the dry ingredients all at once and fold until just combined. This is a pretty wet cookie, but you should be able to roll it into a soft ball. Add a touch more flour as needed.
Mix the granulated sugar and cinnamon in a small bowl. Using a large cookie scoop, scoop dough and roll in cinnamon sugar. Transfer onto lined baking sheets. Bake cookies for about 9 minutes. Note: be sure to adjust the baking time if your cookies are smaller/larger, and if you want them more gooey over your ice cream)