Preheat oven to 300 degrees, and butter a 8×8 baking dish.

Finely grate 2 teaspoons zest and then squeeze 1/3 cup juice from lemons; set aside.

Combine dry ingredients. Whisk together yolks, milk, butter, lemon zest and juice; add to flour mixture; whisk to combine.

Beat egg whites until soft peaks form. Stir 1/3 egg whites into batter to lighten; gently fold in remaining egg whites {batter will be thin}.

Pour into your prepared baking dish; bake until golden, 34-40 minutes. Serve warm or at room temperature.