Mouthwatering one-bowl chocolate cake - Starts at 60

Ingredients

• 1 1/4 cups self-raising flour
• 1/4 cup custard powder
• 2 tablespoons cocoa
• Pinch bicarbonate soda
• 1 cup caster sugar
• 125g butter, softened
• 1/4 cup milk
• 2 eggs
• 1 teaspoon vanilla extract
• 1 cup icing sugar
• 2 tablespoons cocoa, extra
• 2 tablespoons butter, softened
• 1-2 tablespoons hot water
• Chocolate curls, for decoration