1.Adjust oven shelves to allow for the height of the nut roll tins. Preheat oven to 150°C/300°F. Grease and flour lids and inside of tins; place base lids on tins, position tins upright on oven tray.
2.Make cakes according to directions on packets. Divide mixture between tins; position lids on top. Bake rolls about 1 hour. Stand rolls in tins 10 minutes before removing lids; shake tins gently to release cakes onto wire rack to cool.
3.Level cake tops. Cut top off one cake at an angle; discard top. Cut one-third off remaining cake at an angle; keep both pieces of cake. Brush all three cakes all over with jam.
4.Knead ready-made icing on surface dusted with a little sifted icing sugar until icing loses its stickiness. Divide icing into three equal portions; tint yellow, pink and blue.
5.Roll three-quarters of each colour, one at a time, into a 5mm (¼-inch) thickness. Wrap yellow icing around shortest cake; trim away excess icing. Wrap pink icing around medium cake; trim away excess icing. Wrap blue icing around tallest cake; trim away excess icing.
6.Roll remaining icings, one at a time, into a 5mm (¼-inch) thickness. Cut an oval from each colour large enough to cover the tops of each cake; position ovals on tops of cakes.
7.Push candles through icing into centre of each cake until only the wicks are showing (you may need to trim the candles to fit). Secure cakes on cake board with a little jam.
8.Sift ½ cup of the icing sugar into small heatproof bowl, then stir in enough of the water to make a thick paste; tint yellow. Place bowl over small saucepan of simmering water (do not allow water to touch base of bowl); stir until icing is pourable. Working quickly drizzle icing over yellow cake to resemble melted wax.
9.Repeat step 8 to ice the remaining candles, using corresponding colours for the candles.
Equipment: Two 8cm x 17cm (3¼-inch x 6¾-inch) nut roll tins, 30cm (12-inch) round cake board or plate. White icing is also known as fondant (it’s the traditional icing used on wedding cakes). It is available in packets from the supermarket and cake decorating shops.