Slice three even layers from the sponge, between ¼ and ½ in/0.6 cm and 1 cm thick). Moisten the sponge layers with simple syrup. Place one layer in the bottom of an 8-in/20-cm cake ring. Add 10 oz/280 g of the sabayon and spread it evenly. Place another sponge layer in the mold and top with the remaining 10 oz/280 g sabayon. Place the final sponge layer on top.