1. Line an 8 1/2-by-4 1/2-inch loaf pan, preferably metal, with plastic wrap, leaving a 6-inch overhang at each end. Chill in freezer.
2. Melt chocolate in the top of a double boiler over barely simmering water, stirring occasionally until chocolate is smooth. Alternatively, melt in a bowl in microwave for 2 minutes at 50 percent power. Set aside.
3. In a metal bowl, beat eggs and sugar. Set bowl over simmering water in a double boiler base (making sure bowl does not actually touch water). Beat eggs with a handheld electric mixer on medium or with a whisk, until mixture turns pale and thick and registers 140 degrees F on an instant-read thermometer. Continue beating for 3 minutes, remove bowl from pan, and set aside to cool for 3 minutes, then beat in salt, cocoa powder, vanilla extract, and melted chocolate.
4. Mixture will become glossy and stiff.
5. Whip cream in a separate bowl until it holds stiff peaks, then fold gently into egg-chocolate mixture. Remove prepared loaf pan from freezer. Sprinkle 1/3 of biscotti crumbs evenly in bottom of pan, then spread half the chocolate mixture evenly over crumbs; repeat process with remaining crumbs and chocolate mixture, ending with crumbs. Fold overhanging wrap over to cover mixture in pan and freeze for at least 6 hours, preferably overnight.
6. Remove pan from freezer. Unfold plastic wrap from surface of semi-freddo, then invert onto a serving platter. Remove plastic wrap. Slice and serve immediately.
Source: Hannaford fresh Magazine, January - February 2007