Start with the dough.

Mix the yeast with 2 tablespoons luke warm water. Let it sit until is bubbles and shows activity.

Scald the milk and cream until it has a light film on the top. Stir in the butter and let it melt. Cool the mixture.

Beat together the eggs, sugar and salt. Stir in the yeast and mix well.

Stir in 2 cups of flour and the milk mixture. Add more flour, a little at a time, until you have a soft dough. Cover and let rise for an hour or so.

While the dough is rising, make the apples. Peel and slice the apple and put it in a small saucepan. Add all the other ingredients and simmer until the apples are soft and the liquid is almost evaporated. Set aside to cool. 

Preheat the oven to 350° - 

After the dough has risen, flatten it out some and push into a square pan making sure it goes all the way up the sides of the dish. Let it rest for 15 minutes. 

While the dough is rising in the pan, make the custard. Using a whisk, whip all the ingredients together and heat on low until the mixture thickens and begins to look more like a thick sauce. Remove from the heat.

Next, mix up the topping.  Using a pastry blender, cut the cold butter into the sugar. When it is big chunks, stir in the remaining ingredients and mix well. 

Now assemble the kuchen. Pour the apples into the dough. 

Pour the custard over the top of the apples, then top it off with the butter  and sugar mixture. 

Place the pan on a cookie sheet (it's likely to bubble over) and bake for 45 minutes to an hour, or until a knife in the middle comes out fairly clean. It will have some custardy apples on it, but it's supposed to.

Set the dish on a rack to cool. You can serve this hot or cold - It is amazing!