This is VERY loosely based on some of the pie instructions in How to Cook Everything. I've done a lot of adjusting and tweaking. A food processor is used to make the pie dough. I like the filling with all brown sugar, but you can substitute all white sugar, or use a combination. The topping is best with brown sugar. I prefer walnuts for the topping, but any kind of nut is okay. Note: after some experimentation, I've adjusted the streusel.