Ingredients:

  • 1 ¼ cups All-Purpose Flour (plus extra for dusting)
  • ½ teaspoon Fine Sea Salt
  • ½ cup Unsalted Butter, very cold and cut into ½-inch cubes
  • 4–6 tablespoons Ice Water
  • ½ cup Granulated Sugar (custard base)
  • 1 large Egg, beaten (custard base)
  • 1 teaspoon Vanilla Extract (custard base)
  • 1 tablespoon All-Purpose Flour (custard base)
  • Pinch of Salt (custard base)
  • 1 ½ cups Whole Milk
  • ½ cup Unsalted Butter, softened (cake batter)
  • ½ cup Granulated Sugar (cake batter)
  • ¼ cup Light Brown Sugar, packed (cake batter)
  • 1 large Egg (cake batter)
  • ½ teaspoon Vanilla Extract (cake batter)
  • 1 cup All-Purpose Flour (cake batter)
  • ¼ cup Unsweetened Cocoa Powder (Dutch process recommended)
  • 1 teaspoon Baking Powder
  • ½ teaspoon Salt (cake batter)
  • ½ cup Whole Milk (cake batter)
  • 1 cup Semi-Sweet Chocolate Chips

Instructions:

  1. Prepare the Dough: Combine 1 ¼ cups flour and ½ tsp salt. Cut in the cold butter until the mixture resembles coarse crumbs. Slowly add ice water, one tablespoon at a time, until the dough just comes together. Do not overmix.
  2. Chill: Form the dough into a disc, wrap tightly, and refrigerate for 30 minutes.
  3. Roll and Fit: Roll out the chilled dough and transfer it to the 9-inch pie plate. Crimp the edges and prick the bottom generously with a fork.
  4. Blind Bake: Line the shell with parchment paper, fill with pie weights. Bake at 375°F (190°C) for 15 minutes. Remove weights and paper, and bake for an additional 5 minutes until lightly set. Reduce oven temperature to 350°F (175°C).
  5. Mix the Custard Base: In a medium bowl, whisk together the ½ cup sugar, 1 egg, 1 tsp vanilla, 1 tbsp flour, and a pinch of salt until smooth. Whisk in the 1 ½ cups of milk until thoroughly combined. Set aside.
  6. Prepare the Cake Batter: In a separate large bowl, cream the ½ cup softened butter, ½ cup granulated sugar, and brown sugar until light and fluffy.
  7. Add Wet Ingredients: Beat in the second egg and ½ tsp vanilla extract until fully incorporated.
  8. Combine Dry Ingredients: Sift together the remaining flour, cocoa powder, baking powder, and ½ tsp salt.
  9. Finish Batter: Alternate adding the dry ingredients and the ½ cup of milk to the creamed mixture, mixing only until just combined. Fold in ¾ cup of the chocolate chips.
  10. Layer the Custard: Carefully pour the thin Custard Base mixture into the blind-baked pie shell.
  11. Layer the Cake: Using a spoon, gently dollop the thick Chocolate Chip Cake Batter directly on top of the custard in even spots. Do not spread or mix.
  12. Garnish: Sprinkle the remaining ¼ cup of chocolate chips over the top.
  13. Bake: Bake in the preheated 350°F (175°C) oven for 55–65 minutes, or until the cake layer looks baked and the custard underneath is mostly set (a slight jiggle in the center is acceptable).
  14. Cool: Transfer the pie to a wire rack and allow it to cool completely for at least 2 hours before slicing. Cooling is non-negotiable for the structure.