- 1/2 cup fine raw cane sugar
- 1 tablespoon finely grated blood orange zest
- 1 tablespoon finely grated lemon zest
- 1/4 teaspoon salt
- 1/2 cup water
- 1 teaspoon agar powder (see Note)
- 4 cups fresh blood orange juice (from 5 pounds blood oranges), strained through a fine sieve
- 3 tablespoons fresh lemon juice
- 1/2 cup coconut milk
- 1/4 cup almond milk
- One 7-ounce package of ladyfingers, crushed
- 1/4 cup lightly packed pitted prunes
- 1/4 cup hot water
- 1/4 cup unsweetened Dutch-process cocoa powder
- 3 tablespoons pure maple syrup
- 1 1/2 teaspoons finely grated lemon zest
- 1 teaspoon pure vanilla extract
- 1/4 teaspoon salt
- Thinly sliced blood orange, for garnish
- Make the sherbet Line a 9-inch-round cake pan with plastic wrap and transfer it to the freezer. In a bowl, rub the sugar with the blood orange zest, lemon zest and salt.
- Make the sherbet In a medium saucepan, whisk the water with the agar and cook over moderate heat, whisking, just until slightly thickened, 3 to 5 minutes. Add the citrus sugar, blood orange juice and lemon juice and cook over moderate heat, whisking, just until the sugar is dissolves, about 5 minutes. Whisk in the coconut and almond milks and let cool completely, then refrigerate until well chilled, about 3 hours.
- Make the sherbet Strain the sherbet base through a fine sieve into the bowl of an ice cream maker and freeze according to the manufacturer’s instructions. Scrape the sherbet into the prepared cake pan and spread it in an even layer. Press a piece of plastic directly on the surface and freeze until very firm, at least 4 hours or overnight.
- Make the crust In a food processor, pulse the ladyfingers until very finely ground. Transfer the crumbs to a large bowl.
- Make the crust In the food processor, combine the prunes with the hot water, cocoa powder, maple syrup, lemon zest, vanilla and salt and pulse until smooth, scraping down the sides as needed. Scrape the mixture into the large bowl, and using your hands, knead the mixture until an even smooth dough forms. Transfer the dough onto a large piece of plastic wrap and press it into a 9-inch disk. Wrap the disk and refrigerate until well chilled, about 45 minutes.
- Make the crust Unwrap the dough and carefully slide it over the frozen sherbet, pressing it to cover the entire surface. Wrap the cake and freeze until firm, at least 1 hour. Invert the cake onto a plate so the crust is on the bottom. Garnish the top with thinly sliced blood orange, cut into wedges and serve.
The cake can be frozen for up to 5 days.
Agar powder is a colorless type of gelatin made from seaweed that sets without chilling. It is available at some health food shops, Asian markets and from amazon.com.