In 1978, The Junior League of Denver put out a cookbook called Colorado Cache. My first copy literally fell apart and a friend in Leadville was kind enough to send me her copy which she said she never used. Well, it remains one of my favorite books and this recipe comes from there, slightly adapted.
I made it gluten free for a dinner we were going to but you can put white flour in it if you so desire.
Preheat your oven to 350, and grease a 2-quart casserole.
In a bowl, combine 1/2 cup granulated sugar, 1/2 cup brown sugar, 3/4 cup flour (I used gluten free oat flour), 1 tsp salt, and 1/2 cup butter cut in small pieces. Use a pastry blender to make it crumbly.
Peel and slice 5 cups apples, use a more tart apple such as a Granny Smith or Jonathan. Arrange the slices in the casserole.
Pour over this, one shot glass of Amaretto and one shot glass of Grand Marnier (I mixed them together first)
Sprinkle 1 Tablespoon of grated orange rind and 2 tsps of grated lemon rind on top and then lightly sprinkle cinnamon over that.
Spread the four, sugar mixture over the apples, then sprinkle about 1/2 cup chopped walnuts over that. Bake for about 1 hour or until it's brown on top and the apples are cooked. Serve warm with vanilla ice cream or whipped cream.