Streusel is a topping added to various types of pastries and breads. It may also refer to a specific type of brioche pastry with a cream filling or topping. The more common use of the word, however, refers to the crumble sprinkled liberally over muffins, pies, and cakes, particularly coffeecakes. The word is sometimes confused with a pastry known as the strudel, a Viennese morning or dessert sweet with fruit or cheese filling. Streusel and strudel, however, are two separate baked goods.
Also called a crumble or streusel crust, streusel originated in Germany, and the name translates as “to strew or scatter." The three essential ingredients are butter, sugar and flour. Combinations of spices, nuts and other extras are also commonly included in this dessert.
Numerous recipes for this topping exist, many of which suggest varied amounts of butter, sugar and flour. Most bakers recommend cutting the butter into small, easy-to-process pieces, allowing it to soften at room temperature, or occasionally, melting the butter first. Margarine is usually not recommended as a substitute, because it will not bond or bake in the same way that butter will. The resulting taste may also be negatively affected. Brown sugar, however, may be substituted for regular sugar.
Streusels almost always have a higher content of sugar than flour. This ratio separates German streusel from a crumble. The resulting texture resembles the granular feel of sugar. Combined with the butter, the topping may better adhere to the goods on which it is baked.
Variations to the three necessary ingredients are vast. Cinnamon is regularly added, as are some types of nuts, which are usually chopped before being added to the mixture. Coconut is another common option. Oats or meals derived from nuts may give the topping a different texture.
When preparing streusel, the ingredients may be blended together with a hand blender, food processor or utensil or mixed by hand. The hand method is usually recommended by professional bakers in order to produce the best texture. Rather than a smooth, fine blending of the ingredients, streusel is often formed into small, coarse clumps or crumbs.
The crumbs may then be sprinkled lightly or liberally atop other goods that have already been mixed right before entering the oven. Some recipes suggest applying the crumbs part-way through baking. When packed correctly, streusel may be refrigerated and stored for several months.