What is "streusel"?

Streusel is a German-inspired crumbly topping that is commonly used in baking to add texture and flavor to cakes, muffins, pies, and other sweet treats. The topping is made from a mixture of flour, sugar, and butter, which is combined until crumbly and then layered over the top of the baked good before it is put in the oven. Some recipes may also include spices, such as cinnamon or nutmeg, to add extra flavor. As the baked good cooks, the streusel topping becomes golden brown and crispy, adding a deliciously crunchy texture to the soft and moist interior. Streusel can be customized to suit different tastes and preferences, with ingredients such as oats, nuts, or fruit added for extra variety.