These filled pancakes are served during Russia’s Pancake Week (Maslenitsa) celebration before Lent begins. Traditionally they’re filled with caviar, jam, sour cream, or mushroom filling. Posted on November 11, 2021November 11, 2021 by Caitlin Acosta These filled pancakes are served during Russia’s Pancake Week (Maslenitsa) celebration before Lent begins. Traditionally they’re filled with caviar, jam, sour cream, or mushroom filling. Advertisement