1. Preheat oven to 350 degrees F. Spray a 6-cup casserole pan with vegetable cooking spray and place it in a larger baking dish.
2. Combine sugar, flour, salt, and lemon zest in a large mixing bowl and cut in butter until crumbly and evenly distributed. Stir in milk and egg yolks and mix until thoroughly combined.
3. In a separate bowl, use an electric mixer on medium-high to beat egg whites until stiff, but not dry, about 3 minutes. Fold egg whites gently into batter along with lemon juice. Batter should be light and fluffy.
4. Pour batter into prepared casserole pan. Carefully pour hot water into larger surrounding baking dish until it reaches about 1/2 inch up the side of the baking dish. Bake at 350 degrees F for 30 minutes until top is set and springs back when touched, and cake is lightly golden around edges. Let cool in pan for 5 minutes. Serve warm from pan. Top with fresh berries, if desired.
Source: Hannaford fresh Magazine, March - April 2009