Preheat the oven to 350 degrees.
To make the crust, mix the almond flour, oat flour, and date sugar in a large bowl.
Add the flax eggs, and use your hands to press and knead the crust together, until everything is thoroughly combined into a dough.
Use your hands or the bottom of a measuring cup to press out the crust dough into your pan and up along the sides (I used a glass pie pan - if you're worried about the crust sticking, be sure to spray it for easy removal after baking, as the crust is rather delicate). This will take a few minutes, just be patient and get everything as even as possible!
Poke holes in the bottom of the crust using a fork - 8-10 times should be fine. This helps keep the bottom from puffing up when we bake it the first time.
Bake the crust for 20 minutes.
To make the filling, mix the apples, date paste, and cinnamon until thoroughly combined.
When the crust is done baking, remove it and carefully fill with the apple date paste mixture - remember the pan is hot, so be careful!
Bake the pie with just the filling for another 20 minutes. To avoid the edges of the crust burning, feel free to cover just the edges with a bit of foil.
To make the crumb topping, mix the walnuts, dates, lemon juice, vanilla, and cinnamon in a food processor and pulse until the dates are broken up, but there is still a lot of crunchy texture. I pulsed about 20-25 times.
After the pie filling has baked, remove the pan and top with the crumb topping.
Bake the completed pie for another 10 minutes, then let it cool for at least 1 hour before cutting to serve. The pie will be gooey and the crust is fragile, so cut it carefully and use a spoon or spatula to carefully remove it from the pan to avoid baking the crust.
