Choo-choo train birthday cake

Ingredients

• 2 packets butter cake mix
• 225 grams packaged sponge roll
• few drops red food colouring
• few drops blue food colouring
• few drops purple food colouring
• few drops apricot food colouring
• few drops green food colouring
• 8 jube rings
• 1 packet thin licorice
• 1 packet chocolate sprinkles
• 1 wooden skewer
• 1 packet coloured popcorn
• 1 pipe cleaner
• 1 packet wooden iceblock sticks
• 20 round chocolate biscuits
• 1 packet coloured chocolate buttons (as shown)
• 1 icecream wafer
• 1 serving board, straight or curved, 100cm x 20cm (40in x 8in)
• Vienna cream
• 250 grams butter, at room temperature
• 3 cups icing sugar, sifted
• 4 tablespoons milk, at room temperature