Ingredients

  • 3 navel oranges
  • 5 tablespoons sugar
  • 1/2 cup English-style bitter orange marmalade
  • 2 cups half-and-half
  • 1 cup heavy cream
  • 5 large egg yolks
  • 1/2 teaspoon vanilla extract
  • 1/8 teaspoon almond extract
  • 1/4 teaspoon salt
  • Vegetable oil for pan
  • 1 cup slivered blanched almonds (4 1/2 oz)
  • 1/2 cup sugar
  • 3 1/2 tablespoons unsalted butter, softened
  • 2 tablespoons light corn syrup
  • 2 tablespoons heavy cream
  • 1/4 teaspoon vanilla extract
  • 1/8 teaspoon salt
  • 2 teaspoons all-purpose flour
  • 5 oz fine-quality bittersweet chocolate (not unsweetened), finely chopped
  • Special equipment: an instant-read thermometer; an ice cream maker; parchment paper; a 2 1/2-inch fluted round cookie cutter; a pastry brush: an offset metal spatula

Method

  • Finely grate zest from 2 oranges and cover zest with plastic wrap.
  • Squeeze enough juice from all 3 oranges to measure 1 1/2 cups.
  • Bring juice and 3 tablespoons sugar to a boil in a 1-quart saucepan and simmer until reduced to about 3/4 cup, about 10 minutes.
  • Add marmalade and simmer, stirring, until melted, about 1 minute.
  • Remove from heat and cool.
  • Bring half-and-half, cream, remaining 2 tablespoons sugar, and grated zest to a boil in a 2-quart heavy saucepan, stirring until sugar is dissolved.
  • Whisk yolks in a bowl until blended, then add 1/2 cup hot cream mixture in a slow stream, whisking.
  • Stir custard into cream mixture in saucepan and cook over moderately low heat, stirring constantly with a wooden spoon, until thick enough to coat back of spoon and registers 175 to 180F on thermometer (do not let boil).
  • Pour custard through a fine-mesh sieve into a (clean) metal bowl and stir in marmalade mixture, vanilla, almond extract, and salt.
  • Cool to room temperature, stirring occasionally, then chill, covered, until cold, at least 2 hours.
  • Freeze custard in ice cream maker.
  • While ice cream is freezing, oil bottom and sides of a 13- by 9-inch baking pan, then line bottom lengthwise with a sheet of plastic wrap, leaving a 2-inch overhang on each short end.
  • Spread ice cream in pan, smoothing top, then wrap pan in plastic wrap and freeze until ice cream is hardened, about 4 hours.
  • Put oven rack in middle position and preheat oven to 350F.
  • Line 2 baking sheets with parchment.
  • Pulse almonds with sugar in a food processor until finely ground.
  • Cook almond mixture, butter, corn syrup, cream, vanilla, and salt in cleaned 1-quart saucepan over moderate heat, stirring until butter is melted and sugar is dissolved, 2 minutes.
  • Remove from heat and stir in flour, then transfer batter to a bowl and chill until firm, about 1 hour.
  • Roll level teaspoons of batter into balls and arrange about 3 inches apart on baking sheets.
  • Gently flatten balls to about 1 1/4 inches in diameter with a fingertip.
  • Bake cookies in batches until golden brown, 7 to 9 minutes.
  • Slide parchment with cookies from sheet onto a rack to cool completely.
  • Melt chocolate in a double boiler or a metal bowl set over a saucepan of barely simmering water, stirring occasionally, then remove top of double boiler or bowl from heat.
  • Working with 1 cookie at a time, lightly brush undersides of cookies with chocolate and put, chocolate sides up, on rack.
  • Chill cookies in 1 layer until chocolate sets, about 5 minutes.
  • Unwrap pan of ice cream and cut out 12 (2 1/2-inch) ice cream rounds with cookie cutter.
  • Lift out rounds with offset spatula and sandwich each between 2 chilled florentines, chocolate sides in.