Preheat your oven to 350 degrees F (175 degrees C). This ensures that the pie bakes evenly, creating that perfect golden crust.
Prepare your pie crust. Whether you use store-bought or homemade, gently press it into a deep 10-inch pie pan or a standard 9-inch pie pan. If you’d like a flakier bottom crust, par-baking is an excellent option. Bake the crust for 10 to 15 minutes, then let it cool completely before filling to prevent a soggy bottom.
In a mixing bowl, whisk together sugar, flour, and salt. This step is crucial, as it evenly distributes the dry ingredients, ensuring the filling has a consistent sweetness.
In a separate large bowl, whisk together the eggs until they’re light and frothy. This aerates the eggs, which will create a lighter texture in your finished pie.
Add the dry ingredients to the bowl of whisked eggs, along with the buttermilk, lemon zest, and lemon juice. Use a whisk to blend everything until just combined, creating a smooth mixture.
Finally, whisk in the melted butter until evenly incorporated. This step adds richness and flavor to the filling.
Pour the filling into your prepared pie crust, ensuring it's evenly distributed. Take care to avoid overfilling, as the pie will rise during baking.
Transfer the pie to the preheated oven. Bake for 30 minutes if using a 10-inch pan or 20 minutes for a standard 9-inch pan. You’ll want the filling to set but still be slightly jiggly in the center.
Reduce the oven temperature to 325 degrees F (160 degrees C) and bake for an additional 15 to 25 minutes. Keep an eye on it; the edges should be firm while the center remains a little wobbly.
Once done, remove the pie from the oven and place it on a wire rack to cool completely. Allow at least 2 hours for it to set perfectly. Serve immediately, or refrigerate until ready to enjoy, topped with freshly whipped cream and optional sugared cranberries.