Key TakeawaysMadeleine cookies are being recalled over an undeclared nut allergenThe cookies were available for purchase at multiple Costco stores between March and AprilThose who purchased the cookies can return them at a Costco for a full refund.FRIDAY, April 10, 2026 (HealthDay News) — Cookies sold at Costco Wholesale are being recalled because of a labeling error.Costco said certain packages that are labeled as Traditional Madeleines actually contain cookies filled with chocolate hazelnut.That means the packaging does not list tree nuts, as required by the U.S. Food and Drug Administration.Hazelnuts can cause serious or even life-threatening reactions for anyone with tree nut allergies who are unaware that they're in the product.The recalled item affects products labeled:Traditional Madeleines (item #2000012)But the packages actually contain chocolate hazelnut-filled madeleines (item #2011285), AllRecipes said.The cookies were sold between March 30 and April 6 at select Costco stores in:Missoula, Mont.Burlington, Wash.East Peoria, Ill.Bellevue, Wis. Pleasant Prairie, Wis. Chico, Calif.Thornton, Colo. Gilroy, Calif. Bayamon, Puerto RicoPembroke Pines, Fla.Fairfax, Va.The packages include a mix of heart-shaped cookies, some filled with raspberry and others with chocolate hazelnut, AllRecipes reported. More informationThe USDA Food Safety and Inspection Service has more on unreported allergens.SOURCES: AllRecipes, April 8, 2026; Costco Wholesale, news release, April 7, 2026.What This Means For YouConsumers with a tree nut allergy should check any Madeleine cookies purchased from Costco before eating them..Sign up for our weekly HealthDay newsletter