If you don’t count the water, this only has 6 ingredients!
1 C flour
1/2 C butter, diced, at room temperature
1 C sugar
1-1/2 lb Granny Smith apples
1 C water
3 T lemon juice
2 t cinnamon
Preheat oven to 350 F. Peel, quarter, and seed the apples. Slice them thinly into a large bowl and mix with the lemon juice and water. Let stand for 10 minutes.
While the apples are sitting, put the flour and butter in a large bowl and mash them together with a fork until you get clumps. Add the sugar and keep working it together with the fork — it will be pretty lumpy. Put 1-1/2 C of this dough into a greased 9-inch pie pan. Press it onto the bottom and halfway up the sides.
Drain the apples. Arrange on top of the dough and sprinkle with cinnamon. Crumble the remainder of the dough over the apples.
Bake for about an hour, until it’s browned and bubbly. Cool for 30 minutes in the pan and serve warm or at room temperature.