Sri Lankan Sweet Potato Pie

For the Pie Dough:

Whisk together nuts, flour, sugar, salt, and zest in a large bowl. Using your fingertips, work butter in to the dry ingredients until the largest pieces are the size of peas. 

Make a well in the center of the dough. Whisk yolk and egg in a small bowl, and pour into the well. Gradually draw flour mixture into center, kneading until combined. Shape dough into a disk. Wrap in plastic, and refrigerate overnight (up to 3 days).

Let dough come to room temperature; roll out on a lightly floured surface to 1/4 inch thick. Fit dough into a 9 inch spring form pan, pressing and patching so that dough reaches up sides of the plate. Chill in freezer while you make the filling.

For the Pie Filling:

Preheat your oven to 400 degrees. 

Wash and peel the sweet potatoes, and pierce them in several places with a fork. Place on a baking sheet lined with tin foil or parchment paper, and roast for 45-55 minutes or until very tender. Puree in a food processor, mash with a potato masher or in a stand mixer, using the whisk attachment. 

Beat sweet potatoes in medium bowl, adding eggs one at a time, beating well after each addition. Add sugar, beat to incorporate.

Add Sri Lankan Curry, milk, butter, and vanilla, and beat at low speed to incorporate everything evenly and well. 

Pour filling in to prepared crust, and bake at 350 degrees until puffed and firm, 40-50 minutes.