Orange Marmalade Ice Cream Sandwiches with Almond Florentines

PreparationMake ice cream: 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 180°F 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. Make florentines while ice cream hardens: Put oven rack in middle position and preheat oven to 350°F. 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. Assemble sandwiches: 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. Cooks' notes:Florentine cookies (brushed with chocolate but not filled with ice cream) can be made 2 days ahead and chilled, layered between sheets of wax paper, in an airtight container. Ice cream sandwiches can be assembled 3 days ahead and frozen, individually wrapped well in plastic wrap. Let soften in refrigerator 5 to 10 minutes before serving.

PreparationMake ice cream: 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 180°F 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. Make florentines while ice cream hardens: Put oven rack in middle position and preheat oven to 350°F. 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. Assemble sandwiches: 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. Cooks' notes:Florentine cookies (brushed with chocolate but not filled with ice cream) can be made 2 days ahead and chilled, layered between sheets of wax paper, in an airtight container. Ice cream sandwiches can be assembled 3 days ahead and frozen, individually wrapped well in plastic wrap. Let soften in refrigerator 5 to 10 minutes before serving.