In a medium size bowl, whisk together the flour, baking soda, cream of tartar and salt. Set aside.
In a small bowl, mix sugar and cinnamon. Set aside.
Using a stand mixer with a paddle attachment, or a hand-held mixer, cream the room temperature butter for about 1 minute on medium speed. Once the butter is smooth and creamy, add the canola oil and both sugars. Mix on medium until fluffy and light in color.
Scrape down the sides of the bowl and add the eggs, mixing until combined.
Scrape down the sides of the bowl again and with the mixer on low, slowly add in the flour mixture. Mix until just combined.
Cover and chill the dough in the refrigerator for a minimum of 2 hours.
Preheat oven to 375°F. Line baking sheets with silicone baking mats or parchment paper.
Take about 1.5 tablespoons of dough (I use a size 40 scoop) and roll the dough into a ball. Roll the ball in the cinnamon- sugar mixture and place on your baking sheet. Flatten slightly with the bottom of a glass dipped in the cinnamon-sugar mixture.
Bake until the edges are barely browned, about 10-12 minutes. Allow cookies to cool on the pan for 5 minutes before removing to a wire rack to cool completely.
Store cookies in an airtight container at room temperature for 5-7 days or freeze for up to 3 months.
Soft and Thick Snickerdoodle Cookies https://twosugarbugs.com/soft-and-thick-snickerdoodle-cookies/