How to Make It
In a saucepan, bring the sugar, water, light corn syrup and salt to a boil, stirring until the sugar is dissolved; cool. Stir in the orange and lemon juices, transfer to a large glass baking dish and freeze until ice crystals form around the edge, 1 hour. Stir the ice crystals into the center and continue to freeze for 4 1/2 hours, stirring every 30 minutes, until fairly solid.
In a saucepan, combine the sugar with 1/2 cup of water and boil until the sugar syrup reaches 220° on a candy thermometer, about 10 minutes. In a small bowl, sprinkle the gelatin over 2 tablespoons of water and let stand until softened, 5 minutes. Whisk the softened gelatin into the sugar syrup.
In the bowl of a standing electric mixer fitted with the whisk, beat the egg yolks until smooth. With the machine at medium-high speed, carefully drizzle in the hot sugar syrup, then beat at high speed until the mousse base is thick, fluffy and cool, about 5 minutes.
In a bowl, beat the cream until firm. Add the whipped cream and zest to the mousse base; fold in until no white streaks remain.
Scrape the granita with a fork until fluffy and spoon half of it into 8 dessert glasses. Top with half of the orange mousse and almonds. Repeat with the remaining granita, mousse and almonds. Freeze the parfaits until firm, at least 2 hours or overnight.