Preheat oven to 400 degrees F.
Butter the ramekins and coat with white sugar.
Mix 1 tablespoon white sugar and ½ teaspoon lemon zest for topping.
Whisk flour and ⅛ cup sugar in a pot, then blend in corn, cream, and salt.
Cook the mixture until shiny, then stir in butter, egg yolk, lemon zest, and vanilla.
Whip egg white with sugar until soft peaks form, then fold into corn batter.
Fill ramekins, make a channel along edges, sprinkle with lemon zest sugar.
Bake until golden and risen (approximately 25 minutes).
Serve immediately, optionally sprinkle with powdered sugar.