Ingredients:

  • 1 9-inch deep-dish unbaked pie crust
  • 1 large egg white, beaten
  • 3 large eggs, room temperature
  • 1.5 cups granulated sugar
  • 0.5 cup unsalted butter, softened
  • 3 tbsp all-purpose flour
  • 1 cup full-fat buttermilk
  • 1 tbsp lemon juice
  • 1 tsp pure vanilla extract
  • 0.25 tsp salt
  • 0.5 tsp freshly grated nutmeg

Instructions:

  1. Preheat your oven to 350°F (175°C). Place a baking sheet on the middle rack to get hot. Brush the bottom and sides of your unbaked pie crust with the beaten egg white. Note: This creates a seal that prevents the custard from soaking into the dough.
  2. In a large bowl, cream the 0.5 cup softened butter and 1.5 cups granulated sugar. Whisk until pale and fluffy.
  3. Add the 3 large eggs one at a time, whisking thoroughly after each addition.
  4. Stir in the 3 tbsp all purpose flour and 0.25 tsp salt until no white clumps remain.
  5. Slowly pour in the 1 cup buttermilk, 1 tbsp lemon juice, 1 tsp vanilla, and 0.5 tsp freshly grated nutmeg. Whisk until the mixture is completely uniform and silky.
  6. Pour the filling into your prepared pie crust.
  7. Carefully place the pie on the preheated baking sheet in the oven.
  8. Bake for 45 minutes until the edges are set and the top is golden brown.
  9. Check for the jiggle—the center should still move slightly like gelatin, but it shouldn't look liquid.
  10. Remove from the oven and cool on a wire rack for at least 2 hours before slicing. Note: The custard continues to set as it cools.