Finnish immigrants contributed "nisu", a cardamom-flavored sweet bread; "limppu", an Eastern Finnish rye bread; "pannukakku", a variant on the pancake with a custard flavor; "viili" (sometimes spelled "fellia"), a stretchy, fermented Finnish milk; and "korppu", hard slices of toasted cinnamon bread, traditionally dipped in coffee. Some Finnish foods such as "juusto" (squeaky cheese, essentially a cheese curd, like Leipäjuusto) and "saunamakkara" (a ring-bologna sausage) have become so ubiquitous in Upper Peninsula cuisine that they are now commonly found in most grocery stores and supermarkets.