Preheat your oven to 350°F (175°C) and line your baking sheets with parchment paper.

In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy—about 2-3 minutes.

Mix in the pumpkin puree and eggs, stirring until well combined.

In a separate bowl, whisk together the flour, baking soda, cream of tartar, cinnamon, nutmeg, and salt.

Gradually add the dry ingredients to the pumpkin mixture, stirring until fully blended.

Gently fold in the white chocolate chips, distributing them evenly throughout the dough.

In a small bowl, combine the additional sugar and cinnamon for coating.

Scoop out dough using a tablespoon and roll it into balls. Roll these balls in the cinnamon-sugar mixture and place them on the prepared baking sheets.

Bake in the preheated oven for 10-12 minutes or until the edges are lightly golden but the centers remain soft.

Let them cool on the baking sheet for a couple of minutes before transferring them to a wire rack to cool completely.