Sift flour, baking soda and salt into a large bowl. Set aside.
2 cups all purpose flour, 1 tsp baking soda, ½ tsp salt
Whisk together the non dairy milk and flax meal. Set aside.
¼ cup non dairy milk, 3 tsp flax meal
Using an electric mixer with the paddle attachment, beat the butter on high until smooth. With the mixer on medium-low, gradually add the sugar. Once all the sugar is added, cream the butter and sugar on high until the butter has nearly doubled in volume.
½ cup vegan butter, 1 cup granulated sugar
Add the flax and plant milk mix along with the vanilla extract to the creamed butter and sugar. Beat on medium until smooth.
½ tsp vanilla extract
With the mixer on low, add ¼ cup of the flour mixture at a time, scraping down the sides of the bowl when necessary. Beat on medium until a smooth but thick dough forms. There should be no traces of flour. Add the rainbow sprinkles and beat until evenly distributed in the dough.
¼ cup rainbow sprinkles, ¼ cup vegan chocolate chips
Line a baking sheet with parchment paper or a silicone baking mat. Using an ice cream scoop, scoop the dough onto the baking sheet leaving about 2inches of space between each ball of dough. Using a glass cup, gently flatten each cookie sightly ensuring that there is still space between each cookie. Do not overflatten as the cookies will spread when baked.
Place the tray of unbaked cookies in the refridgerator to chill. Meanwhile, preheat the oven to 350ºF. Bake the chilled cookies for 20-25mins. Remove the cookies from the oven and allow them to cool on the baking tray for at least 5 minutes before transfering to a cooling rack to cool completely.