Place a 9-inch springform pan or other stainless steel mold in the freezer. Whip cream to a soft peak and refrigerate until needed.

Melt chocolate over hot water, remove from heat and work in butter; set aside.

For meringue, combine egg whites and sugar in bowl of electric mixer, then place over pan of simmering water. Whisk gently until egg whites are hot and sugar is dissolved. Place on mixer with whip and whip until cooled and increased in volume.

Quickly fold together chocolate mixture and meringue, then fold in whipped cream.

Scrape mixture into prepared mold and cover tightly with plastic wrap. Freeze overnight before serving.

To unmold, dip a small, thin knife in hot water and loosen dessert from side of pan. Unbuckle side of springform and remove. Invert to a chilled platter and lift off pan bottom. Dust very lightly with cocoa immediately before serving. This is great with a rich chocolate sauce.

About frozen souffles:

These ices derive their name from the fact that they are molded in souffle dishes. The capacity of the dish is increased by attaching a paper collar to it, so that when the collar is removed, the frozen mixture extends above the edge of the dish, like a hot souffle. To make a paper collar for a souffle dish, cut a piece of parchment paper about 1/3 as long as the circumference of the dish and about 1 1/2 times as tall. Wrap around the dish and secure with a rubber band, just below the rim of the dish. The top is usually dusted with cocoa powder to imitate the brown crust of a hot souffle.