Preheat oven to 350°. Cover two baking sheets with parchment paper and put them aside.

In a big bowl, mix the butter, shortening, sugar, and eggs until they're all mixed together and smooth.

Sift together the flour, cream of tartar, baking soda and salt. Add to the large bowl and combine until the dough comes together.

In a small bowl, combined the 2 tbsp of cinnamon and sugar, stir together until mixed well.

Using a cookie scoop, scoop dough and form into a round ball.

Place in the cinnamon sugar mixture coating all sides.

Allow the snickerdoodles to cool for 2-3 minutes on the baking sheet so that they can set before transferring to a cooling rack.