Easter nest cake - Good Food Middle East

Ingredients

• 200ml vegetable oil, plus extra for the tin
• 250g plain flour
• 6 tbsp cocoa powder
• 2 tsp baking powder
• 1 tsp bicarbonate of soda
• 280g soft light brown sugar
• 250ml buttermilk
• 2 tsp vanilla extract
• 3 large eggs
• 200g marshmallows
• 100g butter, chopped into chunks
• 2 tbsp cocoa powder
• 75g salted pretzels, crushed
• 4 shredded wheat biscuits, crushed
• chocolate eggs, to decorate
• 150g slightly salted butter, softened
• 300g icing sugar
• 4 tbsp milk