• 280 ml soy milk 1 cup + 2 tablespoons, unsweetened
• 1 Teaspoon apple cider vinegar (or white vinegar)
• 230 g self-raising flour 1+¾ cups
• ½ Teaspoon baking soda
• ½ Teaspoon cinnamon optional, ground; dried
• 180 g caster sugar (¾ cup + 2 tablespoons)
• 90 ml vegan margarine 6 tablespoons, melted; or vegetable oil
• 2 Teaspoons vanilla extract
• 12 Biscoff biscuits crushed into crumbs

For the dairy-free Biscoff buttercream:

• 250 g vegan margarine (1 cup)
• 250 g Biscoff spread 1 cup, smooth
• 500 g icing sugar (4 cups)

To top (optional):

• 6 Biscoff biscuits snapped in half
• Biscoff biscuits crumbs
• Biscoff spread to drizzle, melted; or melted vegan white chocolate