Possible Clues:

• Sugar coating - a danger to aircraft, on roads etc
• I celebrate audibly with cake
• Medium for writing 'Happy Anniversary'
• Napoleon's cover?
• Food coating attractive hospital department ditched
• Here in Paris, song not so topping
• Where 'Happy Anniversary!' may be written
• Bakery concoction
• It may make a topping sweet
• The sweetest part of the cake