Flat, Polish Easter cake/bar cookies. Vilnius (which has a large Polish population) is the capital of Lithuania. This is the Vilnian version of mazurka. It's filled with chocolate, almonds, and dates, & drizzled with icing. Also called mazurek wielkanocny (Easter mazurka, pronounced mah-ZOO-rek bi-el-ka-NUTS-ny); traditionally mazurek is only served as part of the breakfast feast after Easter Mass.