Here is a great halloween recipe called Royal Icing that I found at Britta.com. This one seems to be very easy to make and just dsounds delicious. But personally, anything with the word icing in it just sounds so sweet and yummy to me. This is the hard icing that can clue gingerbread houses together or create that hard icing looking on cookies or cakes.

Makes enough to ice 5-6 dozen sugar cookies.

16 oz powdered sugar (icing sugar)
3 egg whites
1/2 tsp cream of tartar

Beat until peaks firmly hold their shape, and the more you beat it, the firmer it gets. This hardens when exposed to air, but dissolves in water, so keep a moist towel over the bowl while working with it. Use a tight-fitting plastic container to store in the refrigerator for a couple weeks, but the egg whites begin to separate from the sugar any longer than that.