Luxurious Carrot Cake

Ingredients

• 1 cup sunflower oil, plus extra for greasing
• 1 pinch salt
• 100g walnuts
• 3 large large eggs
• 225g soft light brown sugar
• 1 tsp vanilla extract
• 200g carrots, finely grated
• 100g sultanas
• 200g self-raising flour
• 75g wholemeal self-raising flour
• 1 tsp cinnamon
• 1 tsp ground ginger
• 1/4 tbs nutmeg, finely grated
• 1 orange, finely grated zest
• 50g unsalted butter, softened
• 100g cream cheese, at room temperature
• 200g icing sugar
• 1/2 tbs vanilla extract
• 2 oranges