In a stand mixer, or with a hand mixer, cream together the sugar and cold diced butter.
Slowly add the aquaflaxa ( or flax egg) and vanilla while mixing. Cuntinu mixinguntil well incorporated.
Sift the flour and add all at once to the butter mixture and mix until there is no more visible butter. Do not overmix. The dough will be crumbly, it’s normal.
Turn the dough onto your work surface and fraiser the dough (push the dough onto your work surface with the palm of your hand) for 1 to 2 minutes, or until the dough is uniform in texture and coming together.
Push the dough into 2 same-sized balls and wrap in plastic wrap. Refrigerate for a minimum of 1 hour, but overnight is best. At this point, you can also freeze the dough for a later time
Take the dough from the refrigerator, remove it from the plastic wrap and place it between 2 large pieces of parchment paper. Whack it a couple of times with a rolling pin to make it more malleable.
Roll the dough to a uniform 3mm (⅛-inch) thickness, or what is required in your recipe.
Remove the top parchment paper. Lift the rolled dough with the leftover parchment paper and flip it over your tart tin or ring. Drape it so that the dough reaches the bottom of your tin and remove the parchment paper.
Patch any holes you have, press the dough into the bottom edges and the walls of your tart tin, and remove the overhand of dough with a sharp paring knife or by rolling your rolling pin on top of the sharp tart tin edge.
Do any last adjustment to the dough like last dough placement, patched or straightening the top edge of the dough. Refrigerate the dough and tin for 20 to 30 minutes, or until the dough is cold and feel solid.
Prick the bottom of the tart tin all over with a fork and either blind bake or fill according to your recipe. Enjoy!
1 flax egg = 1 tablespoon ground flaxseeds + 3 tablespoon water mixed together. Let it rest for 5 minutes before using.