Buttermilk Slab Pie Recipe

Pie portion plated neatly, showing the contrast between flaky crust and soft custard center.

This Buttermilk Slab Pie Recipe features a rich Southern custard filling made with butter, sugar, eggs, and buttermilk baked in a flaky sheet-pan pie crust and finished with nutmeg. Perfect for feeding a crowd with classic, comforting flavor.

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Course: Dessert

Cuisine: Southern American

Keyword: Buttermilk Slab Pie Recipe

Servings:

Ingredients

2 9-inch pie crusts unbaked
6 tablespoons all-purpose flour
4 cups granulated sugar
2 cups buttermilk
1 cup 2 sticks unsalted butter softened
6 large eggs
2 teaspoons vanilla extract
1/2 teaspoon salt
Ground or freshly grated nutmeg as needed

Instructions

Preheat the oven

Preheat the oven to 350°F (175°C). Prepare a 10 × 15-inch rimmed baking sheet (jelly roll pan) and set it aside.

Prepare the pie crust

If using pre-made pie crusts, remove them from their packaging and allow them to soften according to the package instructions. On a lightly floured surface, stack the crusts and roll them together into a large rectangle approximately 12 × 17 inches in size.

Fit the crust into the pan

Carefully transfer the rolled crust to the prepared baking sheet. Press the dough firmly into the corners and along the sides of the pan. Fold any excess crust along the top edge and flute or crimp the edges as desired. Set the prepared crust aside.

Prepare the filling

In a large mixing bowl, beat the softened butter and granulated sugar together using an electric mixer set to medium speed until the mixture becomes light and fluffy.

Add flour and eggs

Add the all-purpose flour and eggs to the mixture. Continue mixing until the ingredients are fully incorporated and the batter becomes smooth.

Add remaining ingredients

Pour in the buttermilk, vanilla extract, and salt. Mix thoroughly until the filling becomes smooth and well blended.

Fill the crust

Pour the prepared filling into the pie crust. If there is excess filling, fill the crust only up to the top edge of the baking sheet. Sprinkle the surface evenly with ground or freshly grated nutmeg.

Bake the pie

Place the pan in the preheated oven and bake for 35–40 minutes, or until the top becomes lightly browned and the center appears mostly set. The pie may remain slightly jiggly in the center.

Cool before serving

Remove the slab pie from the oven and allow it to cool completely for at least 1 hour before slicing into squares and serving.

Notes

To prepare a gluten-free Buttermilk Slab Pie, substitute the regular pie crust with a certified gluten-free pie crust suitable for sheet-pan baking. Replace the all-purpose flour with a gluten-free flour blend or cornstarch in equal quantity. Ensure all ingredients used are labeled gluten-free to prevent cross-contamination.