Preheat your oven to 350°F (175°C). This is a crucial step to ensure that your pie bakes evenly from the start. A properly preheated oven helps the custard set correctly without overcooking.
In a large mixing bowl, combine 1 cup granulated sugar, 6 large eggs, 1 lemon zest, and ¼ teaspoon lemon oil. Use a whisk to beat the ingredients together until you get a light and fluffy mixture. It should appear slightly pale in color.
Next, slowly add in 3 cups whole milk while continuing to whisk. This will create a smooth custard mixture. Make sure there are no lumps as you mix; the key is to achieve a silky consistency.
Now, pour the pie filling into your prepared unbaked deep dish pie crust. If you’re using a standard 9-inch pie crust, be mindful not to overfill it. You might have extra filling, which can be baked in a ramekin!
Bake the pie for 65 to 70 minutes. After the first hour, cover the crust edges with aluminum foil to prevent burning. You’ll know it’s done when the outer edges puff slightly, and the center is just a bit jiggly.
Once done, remove the pie from the oven and let it cool completely at room temperature. This cooling period is essential because it helps the custard set up properly.
After the pie is cool, gently spread ½ cup lemon curd over the top. This adds a beautiful finishing layer and extra zing to the pie.
Chill the pie in the refrigerator for 1 to 2 hours before serving. This step not only enhances the flavors but also makes it refreshing on the palate.
When ready to serve, slice the pie and top each piece with a dollop of whipped cream. This extra touch transforms your pie into a delightful treat!