METHOD

1. To make the chocolate ganache, place the cream and chocolate in a saucepan over low heat and stir until melted and smooth. Set aside to cool to room temperature.  
   
2. Preheat oven to 160°C (325°F). Place the flour, baking powder, cocoa, sugar, eggs, milk, and vanilla in a large bowl and, using a large whisk, mix to combine. Gradually add the butter and whisk until well combined. Divide the mixture between 2 x lightly greased 15cm-square cake tins lined with non-stick baking paper. Bake for 1 hour 15 minutes–1 hour 25 minutes or until cooked when tested with a skewer. Cool cakes in tins for 10 minutes before turning out onto wire racks to cool completely.
3. To assemble, trim the tops of the cakes and discard. Stack the cakes on a cake board and using a small, sharp knife, cut a shallow square, leaving a 2cm border, from the top cake. 
4. Using a spoon, dig a 1cm-deep hollow in the cake, discarding the crumbs. Using a palette knife, spread the cakes with the ganache. Using a cross-hatch pattern, adhere the biscuits onto the cake to create the ‘basket’. 
5. Adhere the twine to the skewers and press into the basket. Carefully place the balloon between the skewers to secure. Push the extra twine into the ganache to create the ropes and fill the cake hollow with the chocolates. Serves 8-10.