The Berliner is the German doughnut traditionally filled with jam and associated with Carnival. It is a round, yeast-raised pastry deep-fried in fat and usually filled after frying with plum, raspberry, or another fruit jam.
In much of Germany, the pastry is called a Berliner Pfannkuchen, while regional names include Krapfen and Kräppel. It is especially associated with New Year’s Eve and Carnival celebrations. The filling is injected through the side, so the finished pastry does not have a central hole.
A famous prank involves filling one Berliner with mustard instead of jam, although this is not the normal preparation. Outside Germany, the pastry is sometimes sold as a jelly doughnut. The name can cause confusion because “Berliner” also refers to a resident of Berlin, and “Pfannkuchen” means pancake in some German regions.