Desserts - Citrus Semifreddo

3/4 cup sugar
8 large egg yolks
1/4 cup freshly squeezed lemon juice
3 T freshly sqeezed lime juice
2 T limoncello
Pinch of salt
Zest of 1 lemon
Zest of 1 lime
1 cup heavy cream
2 ounces amaretti cookies (about 10 small cookies), crushed

Spray a 9 x 5 x 3" metal loaf pan with nonstick cooking spray. Line with plastic wrap, allowing excess to hang over ends and sides.
Whisk 1/2 cup of sugar, egg yolks, lemon and lime juices, limoncello, and salt in large metal bowl to blend. Stir in zests. Set bowl over a saucepan of simmering water (do not allow bottom of the bowl to touch the water). Whisk egg mixture until it is thick and creamy, and a thermometer inserted into the mixture registers 160F, about 5 mins. Set bowl of custard into another bowl of ice water to cool completely. Using an electric mixer, beat cream and remaining 1/4 cup sugar in another large bowl until firm peaks form. Using a large rubber spatula, gently fold whipped cream into custard. Spoon mixture into prepared loaf pan. Fold plastic wrap over the custard and freeze until frozen, at least 8 hours or up to 3 days.

Unfold plastic wrap. Invert semifreddo onto a platter and peel off the plastic wrap. Cut semifreddo into 1" slices, sprinkle with cookie crumbs, and serve.