To prepare the lemon pudding-cake: Preheat the oven to 325 degrees. Prepare six to eight 6-Ounce Ramekin (or one 8 cup soufflé dish) by coating them well with the soft butter and then sugar. Set the ramekins in a roasting pan that has a kitchen towel laid out on the bottom. The towel allows a bit more insulation for the puddings when baked. Set the roasting pan aside.

In a bowl mix together the flour, 3/4 cup sugar and salt. Rub the zest into the flour mixture. Set aside.

Whisk together the buttermilk, lemon juice and egg yolks. Set aside.

Beat the egg whites with 1 tablespoon sugar until just soft peaks. Be sure not to over beat or they will be grainy and not incorporate into the batter well.

Add the flour mixture to the buttermilk/lemon mixture. Whisk until well incorporated.

Add the egg whites 1/3 at a time and fold them in with a rubber spatula.

Ladle the batter into the prepared ramekins. Fill the roasting pan with hot water up to the middle of the ramekins. Tent with foil. Bake for 20 minutes and then remove the foil.

Bake for another 20 minutes (50 minutes for the large dish) until the cakes rise up above the ramekins, are golden in color and spring back when you touch the tops and a tester comes out with moist crumb, but not wet.

Let them cool to room temperature (the large version needs to sit until the bottom is room temperature or it will not come out cleanly). The pudding-cakes can be served warm, room temperature or even chilled. They can be made ahead and stored in the ramekins until serving time. If you serve them chilled the pudding will be a bit denser, but still lovely.

Run a sharp paring knife around the edge. Invert onto the plate.