Plastic icing is an Australian term for the soft, smooth cake covering also known as rolled fondant. Popular with cake decorators for its ease of handling, it provides a matt icing that can be rolled out like pastry. Plastic icing remains semi-soft, enabling it to be cut, embossed and moulded. Cup cakes, muffins, cookies and celebration cakes can be covered or decorated using plastic icing.
Put the gelatin and cold water into a heat-proof bowl, combine and let the mixture stand until it thickens. Place bowl over a pan of hot water until the gelatin is dissolved and clear. Do not allow it to boil as it will become sticky.
Add glucose and glycerine to the bowl and mix thoroughly. Stir in butter or margarine. When it has almost completely melted, remove the bowl from the heat and stir in vanilla. Cool until lukewarm.
Sieve half the confectioner's sugar into a large bowl. Make a well in the centre and use a wooden spoon to stir in the lukewarm gelatin mixture until all the sugar has been absorbed.
Add the remaining sugar a little at a time, stirring until the stickiness of the mixture disappears. Knead in any remaining sugar. The icing should come together into a large ball.
Place the ball of icing onto a large flat worksurface covered in sieved confectioner's sugar. Knead with the heel of your hand until the icing is smooth and pliable. It should not stick to your hands.
If the icing is still too sticky or too soft, add more sieved confectioner's sugar. If it becomes too stiff, add a drop of water and knead thoroughly until it reaches a flexible consistency.
Use icing immediately or wrap in plastic and store in an airtight container in fridge. When ready to use, bring to room temperature and knead again until soft.
Do not freeze plastic icing. As it thaws, beads of condensation form and the defrosted icing becomes sticky.