1 9-inch deep dish unbaked pie crust (can use homemade or refrigerated)
2/3 cup + 3 TBS dry milk powder
4 large eggs
3/4 cup white granulated sugar
1/4 tsp salt
1 1/2 tsp vanilla bean paste (can use vanilla extract)
2 1/2 cups 2% milk
1/2 tsp ground cinnamon
Ground nutmeg for sprinkling
Whipped cream, optional for topping
First, the custard will be very thin before baking so be sure to use a sturdy pie dish and not one that is disposable and flexible, otherwise you may end up with a big mess when transferring to your oven!
Heat oven to 300F. Line a cookie sheet with parchment paper and spread the milk powder in a thin layer. Bake in oven for 6-9 minutes, watching it constantly and stirring a few times, until the powder has a nutty caramel aroma and is golden brown.
Using the back of a spoon or a coffee grinder, crush into a very fine powder, ensuring there are no larger pieces that could end up in your pie. Set aside to cool.
Raise oven heat to 450F. Line your pie crust with aluminum foil and fill with pie weights or uncooked beans or rice. Bake for 8 minutes, then remove the foil and bake for an additional 3 minutes. Remove from oven and set aside to cool.
Lower oven heat to 350F.
In a mixing bowl, using a fork or flat whisk, combine the eggs until just combined. You do not want to overmix them to the point of creating bubbles or foam.
Add the sugar, salt, vanilla paste, and cinnamon, stirring gently until combined. Lastly, stir in the milk powder and milk.
If your mixture is foamy or has a lot of bubbles, use a spoon to skim off the foam and pass the mixture through a fine mesh strainer to remove additional bubbles and any larger pieces of milk powder.
Pour custard into cooled pie shell and cover the crust edges with strips of aluminum foil or a pie shield. Sprinkle generously with ground nutmeg.
Bake for about 25 minutes, remove the foil, and bake for an additional 15-20 minutes. The pie should still be a little jiggly when you take it out of the oven and it will finish setting up as it cools. Cool on a wire rack, then store in the refrigerator. Serve chilled with whipped cream, if desired.