In baking and pastry making, streusel (German pronunciation: [ˈʃtʁɔʏzl̩] ⓘ) is a crumbly topping of flour, butter, and sugar that is baked on top of muffins, breads, pies, and cakes.

[1] Some modern recipes add spices and chopped nuts.

The mixture can also be layered or ribboned in the middle of a cake.

Some baked dishes which have a streusel topping are streuselkuchen, coffee cake, babka, and apple crisp.

The term is also sometimes used for rich pastries topped with, or mixed with, streusel.