Streusel refers to crumb topping of white sugar, butter and flour which is baked on the top of breads, cakes and muffins. But it is basically a term used in baking which stands for something sprinkled or scattered. Certain modern recipes sometimes add several spices and nutmeats as ingredients to the original one. Although it has its origin in Germany, it often said to be as Swedish or Danish. In some cases, rich pastries when topped or mixed with streusel may also be known as streusel.