- 5 egg yolks
- 1 cup sugar, divided
- 2/3 cup brewed espresso or very strong coffee
- 2 egg whites
- 1/4 teaspoon salt
- 1/2 teaspoon cream of tartar
- 1 cup heavy or whipping cream
- 1 teaspoon vanilla extract
- Line two 9-by-5-inch loaf pans with plastic wrap so excess hangs well over pans' sides. Set aside.
- Pour water to a depth of 2-inches in a medium saucepan and bring to a boil over high heat. Whisk egg yolks and 1/2 cup sugar until light and foamy in heat-safe mixing bowl that will fit securely over the saucepan. Set the bowl over pan, add espresso or coffee, and beat with a mixer at medium speed until thick and tripled in volume, about 10 minutes, scraping down the sides of the bowl occasionally. Remove bowl (be careful of escaping steam) and cool mixture for 15 minutes.
- Clean and dry beaters. Beat egg whites and salt in second bowl at high speed until foamy. Beat in cream of tartar, then beat in remaining 1/2 cup sugar in a steady, thin stream. Set bowl over simmering water and continue beating at medium speed until thick and hot, about 3 minutes. Set aside to cool for 10 minutes.
- Clean and dry beaters again. Whip cream and vanilla in a medium bowl with a mixer at high speed until doubled in volume.
- Fold egg-white mixture into egg-yolk mixture, then gently fold in whipped cream. Pour and spread into prepared pans. Cover with plastic wrap and place in freezer at least 12 hours or up to 3 days. To unmold, remove top plastic wrap, place loaf pan over serving platter, and wiggle semi-freddo free with pieces of plastic wrap hanging over sides. Slice with a sharp knife.
Recipe by Bruce Weinstein and Mark Scarbrough