In a large mixing bowl, combine the flour, sugar, baking soda, poppy seeds and salt.
Next, mix in the plant milk, apple cider vinegar, vegetable oil and the lemon juice and zest. Mix again but don't over-mix. The flour should be just mixed in enough so that there are no lumps.
Equally, divide your cake batter between the two prepared cake tins. If you only have one tin, you can also bake the cakes one at a time.
Bake the two cakes in the oven for 25 minutes or until a skewer comes out clean.
Take your cakes out from the oven and allow them cool fully. In the meantime, let's make the lemon buttercream!