Frozen Lemon Bombe

Directions

1. 1
   Mix the finely grated lemon zest with the sugar.
2. 2
   Whisk the yolks with the sugar and zest until pale yellow. Stir in lemon juice. Heat the cream to scalding in a large saucepan and then pour it into the yolk mixture in a steady stream while whisking continually.
3. 3
   Pour the mixture back into the saucepan and cook over medium heat, stirring continually with a whisk. When the mixture has thickened and simmered for a minute or two, pour it back into the bowl and stir for two to three minutes to cool the cream and to keep it from curdling. Let cool, then chill in the refrigerator.
4. 4
   Add salt and cream of tartar to egg whites. With the electric mixture set on low, beat until stiff enough to hold shape. Slowly raise the speed while gradually adding sugar, about two tablespoons at a time, beating about two minutes after each addition. Add vanilla and beat about five minutes longer at high speed.
5. 5
   Spread in a large circle on a buttered parchment paper on a cookie sheet, and bake at 325 degrees for about an hour, or a bit more. Turn off oven and leave the meringue in the oven several hours, or preferably overnight.
6. 6
   Fold the whipped cream into the lemon curd. Then fold in the chunks of meringue. Pour into a 9- or 10-inch springform pan and freeze, covered with aluminum foil, for at least four hours or up to four days. You will probably need to slip a spatula around the sides before removing the spring form. Serve immediately.