In a small bowl whisk together the flax meal and water until it becomes thick and gelatinous. Set aside.
In a stand mixer with a paddle attachment (or with a strong arm & wooden spoon!!) beat the butter and sugars together until soft and fluffy. Add the flax meal mixture and vanilla. Continue to mix until everything is fully mixed.
In a medium sized bowl sift together the flours, cocoa powder and baking powder. Stir in the salt. With the mixer running on a slow speed slowly add the flour mixture to the butter & sugar mixture. Add all the flour until a soft cookie dough forms. If super sticky add a tablespoon or two of extra flour. You should be able to handle the dough without it sticking to your hands.
Remove the cookie dough from the mixer and place it between 2 pieces of parchment paper. Put the dough in the fridge for 45 minutes until it firms up.
While the dough is in the fridge make a football template out of parchment paper. Draw the shape onto the paper and cut it out. You can make them any size you like. We made a 4 inch (measured pointy end to pointy end) size template which yielded 22 to 24 cookies.
Make the icing for the decoration by placing the icing sugar into a small bowl. Add just enough water to make a thick icing that can be piped easily without running.
Preheat the oven to 350˚F and line 2 cookie sheets with parchment paper.
Once the cookie dough has been in the fridge for 45 minutes take it out and divide it into 2 pieces. Roll out the dough, between 2 pieces of parchment paper, until ¼ inch thick. Place the template on the rolled dough and cut around it with a sharp knife. Carefully transfer the cut out cookies to the lined trays and repeat the process until all the dough has been used up. Re-roll when necessary. Lightly prick the tops of the cookies with a fork. Bake in the centre of the oven for 12 to 15 minutes until lightly browned around the edges.
Once cooked remove from the oven and allow to cool on the trays for 5 minutes. Then transfer to a wire rack to cool fully. Once cooled decorate with icing to look like a football. If making sandwich cookies spread the cupcake frosting over one cookie and place a second on the top.
Optional: Use leftover cupcake frosting to make sandwich cookies