Lost Moon of Poosh Buttermilk Pie

All-Butter Pie Dough:

1. Mix vinegar and water together, then add a few ice cubes. Store in fridge until ready to use.
2. In a large bowl, whisk together flour, sugar, and salt.
3. Add cold, cubed butter to flour mixture, tossing around gently to coat. With pastry blender in one hand, cut in butter while rotating bowl in quarter-turns with your other hand. Stop once the pieces of butter are roughly pea sized. (You’ll want to have some that are a little bigger and some that are a little smaller to maximize the delicious flakiness!)
4. Add ice cold water-vinegar mixture one tablespoon at a time, quickly mixing together with your hands. Continue adding water one tablespoon at a time until the dough comes together. The goal is for the dough to hold together when squeezed into a ball, but with a few dry bits still left in the bowl.
   NOTE: Do NOT add all of the water at once. You don’t want the dough to get so wet that it becomes sticky. You should only be adding 4–5 tablespoons of water total.
5. Wrap dough in cling film, then press into a patty shape about 1-inch thick. Place wrapped dough in fridge overnight. (You could refrigerate for only two hours if you’re in a hurry, but overnight is recommended.)

Par-Baking Pie Crust:

1. Once your dough has chilled and rested, flour your work surface and rolling pin. Retrieve dough from fridge, place on your well-floured surface, and sprinkle top with a little bit of flour.
2. Begin gently rolling out the dough into a circle, making sure to pick up and rotate the dough every few rolls.
3. Once your dough is roughly a 12–14" circle and ¹/₈- to ¼-inch thick, gently place dough into your pie dish. Delicately press dough into bottom and up sides of dish.
4. Trim edges of dough to an even 1" overhang around pie dish.
5. Roll edges underneath themselves to create the crust rim. Crimp or style rim however you like. (Check out King Arthur or Food52 for some snazzy crimping ideas.)
6. Place pie crust in fridge for at least 30 minutes.
7. Move oven rack to the bottom position. Heat oven to 375°F.
8. Retrieve crust from fridge. Dock pie crust (prick bottom all over with a fork).
9. Slightly crumple a piece of parchment paper, then use to line crust, making sure parchment reaches all the corners of the dish. Fill with pie weights or at least 1 lb of dry beans, then place on a baking sheet.
10. Blind bake crust for 14–18 minutes or until mostly dry.
11. While crust is par-baking, in a small bowl, whisk together egg wash. In another small bowl, mix together sugars, cardamom, and salt.
12. Pull crust out of the oven, but don’t turn the oven off yet. Don oven mitts and carefully remove parchment and weights.
13. Brush crust with egg wash, then sprinkle with cardamom sugar.
14. Return crust to oven and bake for an additional 14–18 minutes.
15. Transfer to a wire rack and allow crust to cool completely.

Golden Milk Filling & Final Bake:

1. Once the crust has cooled, move oven rack to middle position. Heat oven to 350°F.
2. In a large bowl, whisk together sugar, Golden Milk, flour, and salt.
3. Whisk in melted butter, sour cream, and vanilla.
4. Add eggs and egg yolk one at a time, whisking until thoroughly combined.
5. Whisk in buttermilk.
6. Pour filling into cooled pie crust. Pop any large bubbles that appear.
7. Cover crust edges with silicone pie crust shield (or aluminum foil strips). Carefully place pie in oven.
8. Bake for 35–45 minutes. The top of the filling will form a thin crust and the edges will set, but the centre should still be jiggly. If your filling is liquidy, give it a few more minutes in the oven.
   NOTE: If you want to be extra sure that your custard filling is fully baked, check the temperature in the centre of the pie, which should be around 180°F.
9. Transfer pie to wire rack. Sprinkle cardamom sugar all over pie.
10. Allow pie to cool to room temperature. Transfer to fridge and chill overnight before enjoying.