[3][4] As the region's countries were already known for their sweet yeast breads, the introduction of coffee in Europe led to the understanding that cakes were a great complement to the beverage.
However, over time, the coffee cake recipes have changed as cheese, sugared fruit, yogurt, soured cream, have been used, leading to a denser, more cake-like structure.
In the 19th century, American cooks also used coffee as an ingredient to thriftily use up leftovers, reducing waste, and flavor the cake.
[13] Streusel is German for "sprinkle" or "strew" and refers to the popular crumbly topping of butter, flour, sugar.
[13] Sour cream is also sometimes used in traditional American coffee cakes to both add a tart flavor and activate baking soda used as a leavening agent.