In a food processor, blend ½ cup (50g) of the rolled oats on high until you have a rough flour, place a small bowl and set aside. Without cleaning the machine, process the hazelnuts into a fine crumb with the texture of sand. Add the coconut oil, maple syrup, salt, and oat flour and process again until the dough comes together. Finally, add the remaining 1 cup of rolled oats and pulse until the oats are chopped, but still have some texture to them. The dough should stick together slightly when pressed between your fingers. If it doesn’t, try adding a bit more maple syrup or processing a bit longer.

Crumble roughly half of the dough evenly over the base of the pan. Starting from the middle, press the mixture firmly and evenly into the bottom, moving outward and upward along the side of the pie dish. The harder you press the crumbs into the dish, the better the crust will hold together. Taking a small section at a time, use the remaining crust to go up the sides, all around the form until complete. Poke a few fork holes into the bottom of the crust to let the steam escape.

Bake the crust, uncovered, for 10 to 15 minutes, until lightly golden. Remove from the oven and set aside to cool.

Pour the filling into the prepared crust, smoothing out the top evenly. Place the pie dish on an even surface in the freezer, uncovered. Freeze for a couple of hours, and then cover the dish with foil and freeze overnight, or for a minimum of 4 to 6 hours, until the pie sets.

Remove the pie from the freezer and let it sit on the counter for 10 minutes before slicing. This pie is meant to be served cold. Garnish with chopped hazelnuts, melted chocolate and flaky salt if desired.