- Separate the eggs.
- Take a bowl and beat the butter and sugar until it becomes a grainy mixture. Now add the flour, lime juice and peel & the salt for seasoning. Mix thoroughly.
- Add in the egg yolks and wish until the mixture turns smooth. Now in another bowl, whisk the egg whites until stiff peaks form.
- Pour this out into 6 ungreased 6-oz custard cups. Transfer these cups into a large baking pan and add 1 inch of boiling water in the pan.
- Insert in the oven and bake for about 40 minutes at 325°F or a few minutes longer. The top should be golden and the knife should come out clean when inserted in the cake!