Vegan Matcha Cake

For the matcha sponge cakes:

• 315 ml soy milk (1 + ¼ cups)
• 1 Teaspoon apple cider vinegar (or lemon juice)
• 350 g self-raising flour (2 + ⅔ cups)
• ¼ Teaspoon baking soda
• 200 g caster sugar (1 cup)
• 2 Teaspoons matcha powder (use 1 teaspoon for a subtle flavour)
• 180 g vegan margarine ¾ cup before melting, melted
• 1 Teaspoon vanilla extract

For the vanilla frosting:

• 120 g vegan margarine (½ cup)
• 1 Teaspoon vanilla extract
• 300 g icing sugar (2+½ cups)
• Splash plant-based milk (if needed)