A kolach, from the Czech and Slovak koláč (plural koláče, diminutive koláčky, meaning "cake/pie") is a type of sweet pastry that holds a portion of fruit surrounded by puffy yeast dough. Common filling flavors include tvaroh (a type of cottage cheese), fruit jam, poppy seeds, or povidla (prune jam). In the United States, the letter "s" is often added to the end of the word kolache to form the word "kolaches"; this is a double plural.