METHOD

1. Preheat oven to 160ºC (325ºF). 
2. Place the water, butter and cocoa in a medium saucepan over medium heat and stir until the butter is melted.
3. Place the flour, bicarbonate of soda and sugar in a bowl, add the cocoa mixture and whisk to combine. Add the eggs, sour cream and vanilla and whisk to combine.
4. Divide the mixture between 2 x 20cm round lightly greased cake tins lined with non-stick baking paper. Bake for 60 minutes or until cooked when tested with a skewer. Allow to cool in the tins for 10 minutes before turning out onto wire racks to cool completely. 
5. To make the frosting, place the cream cheese, vanilla and the icing sugar in an electric mixer and beat for 6 minutes or until light and fluffy. Add the cream and beat for a further 30-45 seconds or until thick. Remove ¼ of the mixture. Add the KitKat double cookies and cream into remaining mixture and fold through.
6. Trim the tops from the cakes and slice in half horizontally. Place one cake layer on a plate and spread with ¼ of the KitKat Double Cookies and Cream icing. Repeat with remaining layers and finish with the plain icing on top of the cake. Serves 6–8