Use a whisk to cream together the 200g margarine and 300g caster sugar in a large mixing bowl. Then pour in the 200g of almond yoghurt, 2 teaspoons of vanilla extract and mix until incorporated. Don't worry if the mixture looks split - it will come together when we mix in the dry ingredients.
Pour in 200ml of the orange juice into the bowl and stir.
Tip in the 400g self raising flour, 2 teaspoons of baking powder, orange zest and 1/2 teaspoon of salt. Whisk into a smooth batter.
Grease a 13 inch x 7 inch baking tin with margarine. Then pour in the cake batter. Place into the oven and bake for 40 minutes or until a knife stuck in the centre comes out clean.
Remove and allow your cake to cool completely before serving. This cake gets better with age and tastes best after refrigerating for 24 hours.