Fasnachts, Fastnachts or Faschnachts are a fatty doughnut treat served traditionally on Fastnacht Day, the day before Lent starts. Fasnachts were produced as a way to empty the pantry of lard, sugar, fat and butter, which were forbidden during Lent. Some English-speaking Protestants tend to refer to the day as Shrove Tuesday, and many consume pancakes as an alternative.
Basel, Switzerland conducts a fasnacht festival annually. The Pennsylvania Dutch territory surrounding Lancaster, Pennsylvania celebrates the custom as well. Most chain supermarkets in the eastern part of Pennsylvania offer fasnachts, although WalMart offers Pączki instead. The pączki is traditionally eaten in Poland on the Thursday prior to Fasnacht Day, although in Polish communities of the US, the celebration is more commonly on Fasnacht Day. Commonly pączki are round, rather than having straight sides, and they are filled with jelly, or sometimes creme filling.
In parts of Maryland, the treats are called Kinklings, and is only sold in bakeries on Shrove Tuesday. The German version is made from a yeast dough, deep fried, and coated or dusted in sugar or cinnamon sugar; they may be plain, or filled with fruit jam. Pennsylvania Dutch fasnachts are often made from potato dough, and may be uncoated, or powdered with table sugar or dusted with confectioner's sugar.
The term now is synonymous with the Carnival season in southern Germany, Switzerland, Alsace and Austria. Although usually written "Fastnacht", there are many local spoken varieties: Fasnacht, Fassenacht, Fasnet etc.
Many churches and fire companies  in Pennsylvania feature Fastnacht sales as a fundraiser.