In a medium saucepan, combine water, sugar, and flour.
Cook over medium heat, stirring constantly, until it thickens slightly (about 3–5 minutes).
Remove from heat and stir in melted butter and vanilla.
Allow the mixture to cool for a few minutes.
Add egg:
Once the mixture is slightly cooled, whisk in the beaten egg until fully combined.
Fill pie crust:
Pour the custard mixture into the unbaked pie crust.
Bake:
Bake at 425°F (220°C) for 10 minutes, then reduce heat to 350°F (175°C) and bake for an additional 20–25 minutes, or until the filling is set and lightly golden on top.
Cool and serve:
Let the pie cool completely before slicing. It can be served plain or with a sprinkle of cinnamon or a dollop of whipped cream.
Tips:
This pie is meant to be simple and slightly translucent, so don’t expect a thick custard like modern pies.
For extra flavor, some people add a teaspoon of lemon juice or a pinch of nutmeg.
If you want, I can also give you a version that uses condensed milk—a slightly richer take on this Depression-era classic. Do you want me to do that?
