Preheat the oven to 400ºF and line two baking sheets with parchment paper or silicone baking mats.
In a mixing bowl, whisk together the flour, cream of tartar, baking soda, salt, cornstarch, 2 tsp of cinnamon, nutmeg, allspice, and ginger.
1¼ cup +2 tbsp all purpose flour, 1 tsp cream of tartar, ½ tsp baking soda, ¼ tsp salt, 1 tbsp cornstarch, 1 tsp + 1 tbsp ground cinnamon, ½ tsp ground nutmeg, ¼ tsp allspice, ¼ tsp ground ginger
In another large mixing bowl or stand mixer, beat the softened butter with a paddle attachment on high until soft and fluffy. Gradually add the 1½ cups sugar and beat until the butter doubles in volume, about 3 minutes. Add the applesauce and beat on medium until smooth.
¼ cup +2 tbsp vegan butter, softened, ¾ cup +3 tbsp granulated sugar, ⅓ cup unsweetened applesauce
Gradually add the dry mixture into the wet mixture while beating on low. Once there are no traces of flour left, add the diced apple and beat on med-low until a tangible dough forms. If the cookie dough is very soft, leave the entire bowl in the fridge for at least 30 minutes to allow the dough to harden.
½ small apple, finely diced
Combine the 3 tbsp of sugar and 1 tbsp of ground cinnamon for rolling the dough.
1 tsp + 1 tbsp ground cinnamon, ¾ cup +3 tbsp granulated sugar
Scoop ~⅓ cup-sized (or ice cream scoop) cookie dough balls, roll them in the cinnamon sugar, and place them onto two baking sheets, leaving as much space as you can. Gently flatten the cookie dough with a round glass or the bottom of a measuring cup until the cookies are about 1 inch thick. There should still be at least 2cm of space between the cookies, as they will spread when baked.
Bake the cookies for 10-15 mins, or until golden brown in colour. Allow the cookies to cool on the baking sheet for at least 10 minutes before transferring to a cooling rack to cool completely. The cookies will be very soft when warm!