This Danish tradition, celebrated in or around February is a mix of the UK's version of Halloween and carnival type occassion!
Although a 'fast' was originally observed, the bakeries are now full of Fastelavn boller (buns) - Large pastries smothered with different icings or filled with a variety of fruit jams,
The festival's origins weren't very pretty - involving beating a cat from a barrel and then chasing it out of the village, this was to symbolise 'chasing away bad luck/evil spirits.
Today, a barrel is filled with sweets, hung up and the children hit it until the sweets are released (as like a pinata!)
The children then dress in 'scary' costumes & go door to door - singing a tradition song and requesting treats !
Carnival type games are played and sung!
http://en.wikipedia.org/wiki/Carnival_in_Denmark