Preheat the oven to 350°F (180°C) and prepare a 9x13 baking dish by spraying it with non stick spray and lining it with parchment paper so that there is a parchment paper overhang on each side. Set aside.
Add the all purpose flour, white sugar and salt for your shortbread crust to a mixing bowl and mix together. Then add in the vegan butter.
Use your hands to break up the butter with the flour until it reaches a crumbly texture, then gradually start to form it into a big ball of dough.
Place the dough into the prepared dish and use your hands to smooth it down across the bottom of the dish into a smooth even layer.
Place into the oven and bake for 20 minutes until the edges are lightly browned. When it's done, remove from the oven, leaving the oven on, and let it sit on the countertop while you prepare the lemon filling.
Add the freshly squeezed lemon juice, sugar, lemon extract, salt, coconut cream, cornstarch and turmeric to a saucepan and whisk as it heats until the ingredients are well combined. Then switch to a wooden spoon and keep stirring. It will suddenly start to thicken dramatically and you'll know it's done.
Pour the lemon filling out over the top of the shortbread crust and smooth down.
Bake for 15 minutes at 350°F.
Remove from the oven and place the dish onto a a wire cooling rack on the countertop for an hour to cool down before placing the whole dish into the fridge to chill completely.
Let it chill in the fridge for at least 2 hours until completely chilled before slicing into squares. It's even more ideal if you can leave it overnight to really firm up before slicing.
When chilled, remove it from the fridge and lift the dessert out of the dish using the parchment paper overhang. Place onto a wooden board and cut into 24 squares.
Then sprinkle some powdered sugar over the top and you're ready to serve!