How to make Victoria sponge cake

Ingredients

• 225g self raising flour
• 225g sugar
• 200g softened butter
• 25g vegetable oil
• 4 eggs
• 1 tsp vanilla extract
• 1/2 a lemon lemon zest
• a pinch salt
• 100g butter
• 200g icing sugar
• 2 tsp vanilla extract
• 2 tbsp milk
• a jar jam of choice
• 1 tbsp icing sugar