Rhubarb and Custard Cake

Ingredients

• 100g (scant 1 cup) plain flour
• 50g (1/4 cup) brown or Demerara sugar
• 50g (3 tbsp + 1 tsp) dairy-free margarine
• 400g (3 cups + 2 tbsp) self-raising flour
• 240g (1 cup + 3 tbsp) caster sugar
• 2 tsp baking powder
• 360ml (1 ½ cups) soya or rice milk
• 160ml (2/3 cup) rapeseed or another flavourless vegetable oil
• 100g (1/2 cup) tinned cooked rhubarb, drained and chopped
• 2 tbsp vanilla extract or essence
• 1 x quantity Custard Buttercream icing (see ingredients below)
• 30g (1/8 cup) tinned cooked rhubarb
• rhubarb and custard sweets
• 75g (5 tbsp) dairy-free margarine
• 75g (5 tbsp) vegetable fat
• 750g (6 cups) icing sugar
• 2 tbsp dairy-free custard powder
• 1 tbsp vanilla extract
• 40–60ml (2 tbsp + 2 tsp–4 tbsp) soya or rice milk