Whisk together the flour, cream of tartar, baking soda, ground cinnamon, and salt. In a separate bowl, whisk the sugars with the oil and water until smooth and well incorporated, about 2 minutes.
Add the dry mixture to wet and mix with a rubber spatula until just combined and you can no longer see any flour, being careful not to overmix.
In a small bowl mix together the cinnamon sugar. Roll the cookie dough into 1.5-2-inch sized balls using a cookie scoop (or a spoon and your hands). Carefully roll in the cinnamon sugar and place on a lined baking sheet with plenty of space in between each cookie.
Put the baking sheets with the cookies in the freezer for 30 minutes. When there are about 5 minutes left, preheat your oven to 350°F.
Place the cold cookie sheets directly in the oven from the freezer and bake for 14 - 16 minutes. (I like to do this in two batches for the best results.) Remove from the oven and lightly flatten each cookie with the bottom of a glass to give them that signature snickerdoodle crinkle.
Let cool slightly.