In a food processor, add the flour, salt, sugar, and butter and pulse until it reaches pea-like pieces. Add in the ice water, a tablespoon at a time until it comes together (you likely won't use it all!). Form into a thick round risk, wrap in plastic wrap and refrigerate for 1 hour to set up.
Meanwhile, preheat oven to 325F.
Mix together the chia and almond milk and refrigerate for 20 minutes.
In a food processor, puree the chia egg (the chia and almond milk mixture), maple, sugar, cornstarch, vanilla, vinegar, butter, salt and cinnamon.
Roll the dough out to less than 1/4 inch. Using a glass, cut out circles and nestle into a greased muffin tin. Poke holes in the bottom and sides using a fork and bake for 10 minutes.
Add the filling 2/3 of the way up and bake for another 20-25 minutes until lightly golden brown. Allow to cool slightly to set.