Apple streusel is a traditional German cake that features 3 layers of flavor. The first layer is a butter batter that is spread across the bottom of a buttered and floured spring-form cake pan. The second layer consists of thin slices of apple and the final topping is the streusel.
In a medium bowl, mix brown sugar, 3/4 cup flour, and cinnamon.
Cut in the butter with a fork until crumbly and then stir in walnuts. You can also use a hand mixer or countertop mixer to make the streusel. Don’t overdo it. You want the mixture to be crumbly.
Add the butter and sugar plus the 3 eggs, yogurt and vanilla, the 3 1/4 cups flour, baking powder, and baking soda.
Select the pizza dough or pasta dough setting or the cake bread setting if your machine has one. Remember to remove the batter before the baking cycle begins if using the cake bread setting.
An alternative is the basic dough setting, but remove the batter before the rising cycle starts.
Preheat oven to 350 degrees F (175 degrees C) and then butter and flour a spring-form cake pan.
Pour the batter into the spring-form pan and spread it around the bottom so it’s even distributed to the sides of the pan.
Top the batter with the thin slices of apple.
Top with the streusel and pat down with a spoon to integrate it into the apple slices.
Lightly fluff up the streusel dressing with a fork.
Bake 50 to 60 minutes in the preheated oven, or until a toothpick inserted in the center comes out clean.
Cool in the pan on a wire rack 15 minutes. Remove spring form pan, and let the cake cool completely. Slice and serve.