Lemon Custard Cake

INGREDIENTS:

1 cup all-purpose flour.
1/4 teaspoon salt.
4 large eggs, separated.
1 and 1/4 cups granulated sugar.
1/3 cup unsalted butter, melted.
1/2 cup fresh lemon juice.
2 teaspoons lemon zest.
1 and 1/2 cups whole milk.
Powdered sugar, for dusting.

DIRECTIONS:

Grease a 9×9 inch baking dish; preheat oven to 350°F (175°C).
Whisk flour and salt in a bowl. In another, cream egg yolks and sugar.
Add melted butter, lemon juice, and zest to yolks. Mix well.
Fold in flour mixture gently, then stiff egg whites, avoiding deflation …