The crunch comes from the crushed Ferrero Rocher bits; the silky layer is hazelnut frosting. Our Chocolate Hazelnut Cake at Sweet Reserve Bakery in Winfield starts with moist chocolate sponge, layered with hazelnut frosting and crunchy crushed Ferrero Rocher pieces. Smooth white buttercream covers the cake, with hazelnut frosting swirls and extra Ferrero Rocher pieces on top. 6-inch (serves 6–10) 8-inch (serves 12-18) 10-inch (serves 25-35)