Into a small bowl, add ground flaxseed and water. Stir to combine and set aside for 5 minutes.
Make the cookie dough:
Into a large mixing bowl, add vegan butter, vegetable shortening, granulated sugar, flaxseed mixture, and vanilla bean paste. Using a hand mixer or stand mixer, cream together the ingredients.
Add all-purpose flour, cream of tartar, baking soda, and salt. Blend to combine; the dough will be crumbly.
Using your very clean hands, shape the dough into 24 balls approximately 1-inch in diameter.
Make the cinnamon sugar:
Into a small bowl, add granulated sugar and ground cinnamon. Stir to combine.
Roll the dough:
Roll balls of dough in cinnamon-sugar mixture to coat.
Bake the cookies:
Onto baking sheets, arrange cookie dough balls at least 2 inches apart.
Bake for 8 minutes.
Cool on the baking sheets for 5 minutes then transfer to cooling racks.
Cookies will stay fresh for up to 1 week in an airtight container.