Prep: 1. Preheat oven to 325. 2. Melt butter. 3. Zest 1 teaspoon lemon zest and juice both lemons. 3. Separate eggs. Make 1. In a medium bowl, combine flour, baking powder, and salt. 2. In a large bowl, whisk together together egg yolks with 1/2 cup granulated sugar until pale and smooth. Whisk in melted butter, lemon zest and juice, milk, and flour mixture. Place mixture in the refrigerator. 3. While egg yolk and flour mixture is chilling, use an electric mixer to beat egg whites with 1/4 cup granulated sugar until stiff peaks form, about 5 minutes. 4. Fold egg whites into chilled batter. 5. Butter eight 6-ounce ramekins or a 2-quart baking dish. Set in a shallow baking pan. 5. With a ladle, divide batter among ramekins, keeping sides clean. Pour enough hot water into the outer baking pan to come halfway up sides of ramekins. 6. Place in oven and bake until cakes are puffed and slightly golden on top, 30 minutes. 7. Dust with confectioners' sugar and serve immediately.
Baking the cakes in a water bath creates an even, gentle cooking environment, resulting in a moist, silky texture. Individual ramekins make for great presentation, definitely use them if you have them!