Beat margarine, sugar and vanilla with handheld mixture until creamy, about three minutes.
In small measuring cup, whisk together almond milk and canola oil. Slowly add to sugar/margarine mixture.
Combine flour, cornstarch, cream of tartar, baking powder, baking soda and salt, in large measuring cup. Add to large bowl. Beat until soft dough forms.
In small bowl, combine ¼ cup sugar and 1 tsp cinnamon.
Divide dough into 24 equal pieces for large cookies or 48 equal pieces for mini cookies.
Roll into balls and coat with cinnamon sugar.
Bake 12 minutes for large cookies or 7 minutes for mini cookies. Cookies will be puffed up. Let cool on baking sheets for 5 minutes, then transfer to baking sheet.
Recipe by The Emotional Baker at https://theemotionalbaker.com/snickerdoodle-cookies/