1½ cups unsalted butter, melted and cooled slightly
2 teaspoons vanilla extract
1¼ cups whole buttermilk, room temperature
Lemon Whipped Cream (recipe follows)
Garnish: edible flowers, lemon slices
Instructions
Preheat oven to 400°. Place oven rack in bottom third of oven.
On a lightly floured surface, roll Buttermilk Pie Dough into a 16x12-inch rectangle. Transfer to a 13x9-inch baking pan, pressing into bottom and up sides. Trim excess dough to ½ inch beyond edge of pan, if needed. Fold edges under, and crimp as desired. Freeze for 15 minutes.
In a large bowl, whisk together sugar, flour, salt, lemon zest, and nutmeg. Whisk in eggs, melted butter, and vanilla until combined. Slowly add buttermilk, whisking until just combined. Pour into prepared crust.
Bake for 15 minutes. Reduce oven temperature to 325°. Bake until the edges are set but the center still has a slight jiggle and an instant-read thermometer inserted in the center registers 200°, 25 to 30 minutes. The pie will be puffed when removed from the oven and then deflate slightly as it cools. Let cool completely on wire rack. Refrigerate until ready to serve. Serve chilled with Lemon Whipped Cream. Garnish with edible flowers and lemon, if desired.
Recipe by Southern Lady Magazine at https://southernladymagazine.com/buttermilk-slab-pie-recipe/