Dissolve the yeast in the warm milk in a large bowl and let it sit for 5 minutes to proof.
Add the sugar, butter and eggs and mix well.
Mix in the flour a cup at a time. Use a wooden spoon to make it a little easier. If the dough it too thick to mix, use your hands to mix it and knead it right in the bowl. It will be pretty soft.
Let the dough rise for an hour.
Prepare the crumb and apple topping:
Combine 1 cup of flour with ½ cup sugar. Cut in ½ cup butter, add the vanilla, and mix until crumbly.
Chop apples, you want about 1/4 inch size. Mix with cinnamon.
Finishing the cake:
Preheat oven to 350ºF . Grease the bottom and sides of a 9 x 13-inch baking dish.
Stir batter down. Spread in greased pan. Sprinkle apples evenly over batter then cover with crumb topping evenly. Cover, let rest for 10 minutes.
Bake in for 20 to 25 minutes until golden brown on edges.
You can sprinkle cake with powdered sugar or vanilla sugar right before serving.
This cake isn't overly sweet like American coffee cakes. So if you wanted a dessert-like cake, serve with whipped cream and/ or ice cream if you like. Wonderful with coffee or tea!