Prepare the Baking Dish

• Preheat oven to 325°F (165°C).
• Line the bottom of a roasting pan or 9×13-inch baking dish with a flat kitchen towel.
• Lightly coat 8 (6-ounce) ramekins or an 8-inch square baking pan with cooking spray.
• Place the baking dish inside the roasting pan.
• Bring about 7 cups of water to a boil and set aside.

Make the Batter

• In a large bowl, whisk together egg yolks, 1 cup of sugar, milk, lemon zest, lemon juice, melted butter, vanilla, and salt.
• Whisk in flour until smooth.

Whip the Egg Whites

• In a separate bowl, whisk egg whites until foamy.
• Add remaining 1 tbsp sugar and continue whisking until soft peaks form.

Combine the Mixtures

• Gently fold half of the egg whites into the lemon batter until just combined.
• Add the remaining egg whites and whisk gently until smooth and fluffy.

Bake in a Water Bath

• Pour batter into the prepared pan or divide evenly among ramekins (about ⅔ cup each).
• Place the roasting pan on the oven rack and carefully pour in hot water until it reaches halfway up the sides of the ramekins.
• Bake until the top is set and a toothpick inserted halfway comes out clean:
  • For a single baking dish: 35-40 minutes
  • For ramekins: 32-34 minutes

Cool & Serve

• Carefully remove the ramekins or pan from the water bath and place on a wire rack.
• Let cool for at least 15 minutes.
• Serve dusted with powdered sugar, lemon zest, or a dollop of whipped cream.