Donut fillers are a type of food item that is used to fill the center of a donut. Common examples of donut fillers include creams, jams, custards, and fruits. Creams are a popular choice for donut fillers, as they are creamy and sweet, and can be flavored with a variety of ingredients. Creams are usually made from dairy products such as milk, cream, and butter, and can also be combined with other ingredients such as sugar, eggs, and flavorings.