Unroll pie crust onto lightly floured surface, use a glass or biscuit cutter between 3 1/2" to 4" to cut out 6 pastry rounds. Press into prepared muffin tin to make pie crust base.
Peel and dice apples into small bite sized pieces.
In a small bowl toss together diced apples,chopped walnuts, flour, cinnamon, apple pie spice, lemon juice, salt, and butter- stirring to combine all ingredients well.