Preheat your oven: Preheat oven to 350°F (180°C).
Prepare the chia or flax egg: In a small bowl, mix together the ground chia or flax and warm water and set aside to thicken. Chia thickens almost instantly, while flax may take up to 10 minutes to thicken.
Mix the dry ingredients: In a large bowl, mix together the flour, baking powder, and salt. Set aside.
Mix the wet ingredients: In a large mixing bowl, use a hand mixer or a stand mixer fitted with the paddle attachment to cream the vegan butter and sugar together until fluffy, about 3 minutes. Add the vanilla extract, almond extract, and the thickened chia or flax egg, then mix again until well combined.
Form the dough: Add the butter mixture to the flour mixture and stir to form a dough. If the dough does not come together, add water 1 teaspoon at a time (up to 3 teaspoons total) until it just comes together.
Roll out the dough: Place the dough between two sheets of parchment paper and roll it out to about ¼ inch (6 mm) thick. Transfer the parchment paper with the rolled dough onto a large baking sheet. Chill in the freezer for 15 minutes or in the fridge for 30 minutes, until firm.
Cut out shapes: Once chilled, use your favorite cookie cutters to cut out shapes. Place the cutouts on a parchment-lined baking sheet. Re-roll any remaining dough and repeat until all the dough is used, chilling as needed.
Bake the cookies: Bake for 8–11 minutes, or until the edges are just lightly golden. Let the cookies cool completely before decorating.