National Hazelnut Cake Day is observed in the United States every June 1, celebrating the delicious dessert made with hazelnuts. The term "hazelnut cake" encompasses various cakes that incorporate hazelnuts, often replacing wheat flour with finely ground hazelnuts or adding chopped hazelnuts to the batter. A notable example is the Italian hazelnut cake, or torta di nocciole, which originates from the Piedmont region and must contain at least 35% toasted Piedmont hazelnuts, along with eggs, sugar, and butter. Traditionally served plain with a dusting of powdered sugar, it can also be enjoyed with whipped cream or zabaione. Another famous hazelnut cake is the Kyiv cake from Ukraine, featuring layers of meringue and buttercream. While the origins of National Hazelnut Cake Day are unclear, it encourages people to indulge in this treat, whether by baking at home or purchasing from a bakery, and sharing their cake on social media with the hashtag #NationalHazelnutCakeDay.