In South Korea, what baked treat is commonly exchanged during Christmas celebrations?

Christmas Cake

What fruit is traditionally placed in Christmas stockings as a gift? Who tricked Jacob, giving him Leah as a wife instead of Rachel? In swimming, what's the name of the process swimmers use to turn quickly underwater after touching the wall? Which European capital city annually donates a large Christmas tree displayed in London's Trafalgar Square? Which inventor is credited with developing the safety elevator?