Crumbl Snickerdoodle Cookies Recipe

In a large mixing bowl, combine the flour, cream of tartar, salt, baking powder, and baking soda. Mix well.
In a separate large mixing bowl, cream together the butter and both sugars until soft using an electric mixer. Add the eggs, vegetable oil, and vanilla extract and mix again until fully blended.
Add the dry ingredients to the wet ingredients and blend until fully incorporated. The mixture will be very crumbly at first. Continue mixing and kneading with your hands if necessary. Cover the bowl and refrigerate for 30 minutes.
To make the cinnamon sugar coating, combine the white sugar and cinnamon in a small bowl and mix well.
Preheat the oven to 350°F and line a large baking sheet with parchment paper.
Scoop the chilled cookie dough with a large (3-tablespoon) cookie scoop or a 1/4-cup measuring cup. Use your hands to roll each scoop into a smooth, round ball. Coat the balls of dough with cinnamon sugar and place them 2 inches apart on the baking sheet. Use a glass to press them flat. Bake for 9 to 10 minutes, checking periodically.
As soon as the cookies come out of the oven, use a flat-bottomed glass to gently press them into round disks, being careful not to flatten them too much. The edges of the cookies should appear cracked after pressing.
Allow the cookies to cool on the baking sheet for 2 minutes. Then transfer to a cooling rack to cool completely.