Here's my recipe for Sour Cream Apple Pie. Found it in an ancient (okay, not ancient, only about 40-50 years old) Martha Dixon cookbook and fell in love at first bite. I'm not a huge fan of traditional apple pies, with the cloying sweetness some get. This one is still pretty sweet, but I like the filling better.
Sour Cream Apple Pie (Martha Dixon)
1 c. sour cream
2 T. flour
3/4 c. sugar
1/4 t. salt
1 t. vanilla
1 pie crust (homemade or frozen, doesn't matter)
3 cups tart Michigan apples, diced (I used Macintosh)
Beat together cream, sugar, flour, salt, vanilla, and egg. Add apples. Pour into 9-inch unbaked pie shell and bake at 400F for 25 minutes. Top with crumb (see recipe below).
Crumb topping (This is as is in the cookbook, but I find that it doesn't work. It turns into a sort of sugar crust. So, if you have a good recipe for crumb, go ahead and use that)
Mix 1/2 c. brown sugar, 1/3 c. flour, and 1/4 c. butter. Sprinkle on top of pie and bake 20 minutes more.
Let cool before serving. If you cut into it too soon, the filling will be soupy as it needs to set.