In a medium bowl, combine almond flour and all-purpose flour. Cut in butter until the mixture resembles coarse crumbs. Sprinkle water over the crumbs and mix until the dough comes together.
Press the dough into a 9-inch pie pan. Place in the refrigerator to chill while you prepare the filling.
In a large bowl, combine apples, sugar, flour, cinnamon, nutmeg, and salt. Mix together until the apples are evenly coated.
Spread the apple mixture into the chilled pie crust. Brush the edges of the crust with the beaten egg. Sprinkle with sliced almonds. Place the pie on a baking sheet.
Bake for 40-45 minutes, or until the apples are tender and the crust is golden brown.
Serve warm or at room temperature.
Interesting Facts
Almond flour is a great source of protein, fiber, and healthy fats.
Apples are a good source of vitamin C, fiber, and antioxidants.
This pie is a great way to use up any leftover apples.