Milk Chocolate-Banana Cake with Gianduja Sorbet

To make the sorbet: Place the chocolate and cocoa powder in a stainless mixing bowl and form a well in the center. Bring the water, sugar, and salt to a boil and cook until the sugar is completely dissolved and the mixture thickens just slightly to a clear syrup. Pour a little of the hot syrup into the center of the chocolate. Let stand 30 seconds, then begin stirring with a spatula from the center outward until the mixture forms a paste. Slowly whisk in the remaining syrup. Strain through a small mesh strainer. Allow to cool to room temperature. Put the mixture in an ice cream freezer and freeze according to manufacturer’s instructions. Place in the freezer at least overnight.

To make the lattice: Lightly spray a silicone liner mat with vegetable oil spray and blot any excess. Prepare two large doubled piping bags with 1/8-inch tips (they will hold the hot syrup). Heat the sugar and corn syrup in a heavy small saucepan over medium-high heat until the mixture liquifies. Swirl together; do not stir. Wash down any crystals which form on the sides of the pot with a small wet brush. Cook until the syrup turns a deep golden color, and reaches 320 F on a candy thermometer. Remove the pan from the heat and place in a large bowl of ice to cool the caramel and stop it from cooking further. Stir the chocolate into the sugar mixture until smooth. Put some of the mixture in one of the piping bags and pipe four 2-inch-by-10-inch lattices on the prepared silicone liner. Use the second bag to finish making a total of 8 lattices. Allow the lattices to cool and set. Rewarm slightly in the oven until flexible, then bend into an “L” shape. Let cool. Set aside in a cool dry place.

To make the striped chocolate panels: Tape flexible acetate (plastic) to the back of a flat sheet pan or tray. Grate one fourth of the white chocolate. Melt the remaining three-fourths of the white chocolate in the top of a double boiler over barely simmering water. Heat to no more than 115 F. Remove from the heat and set the bowl on a towel or napkin to hold it steady. Stir in the grated white chocolate and cool the mixture to 90 F. Pour the chocolate on the acetate and spread very thin into a rectangle at least 9 inches wide with a flat metal spatula. Pull a chocolate comb or comb reserved for this use lengthwise through the setting chocolate, creating fine lines all the way down to the acetate. Place in the refrigerator to set.

Meanwhile, grate one fourth of the dark chocolate. Melt the remaining three-fourths of the dark chocolate in the top of a double boiler over barely simmering water. Heat to no more than 115 F. Remove from the heat and set the bowl on a towel or napkin to hold it steady. Stir in the grated dark chocolate and cool the mixture to 90 F. Take the chilled white chocolate out of the refrigerator. Spread a thin layer of the dark chocolate over it. Let cool until the chocolate loses its gloss. Score across the rectangle into eight 1-inch wide panels, all the way down to the acetate. Return to the refrigerator to harden. When ready, bend the acetate along the scored lines, then peel the acetate from the chocolate panels.

To make the banana bread: Preheat the oven to 350 F. Butter a 9-inch loaf pan and lightly dust with flour. Cream the butter and sugar together on medium speed in an electric mixer. When light and fluffy, beat in the eggs one at time, then add the vanilla extract. Slowly beat in the banana chunks, creaming the mixture until well blended. Mix the flour, salt, and baking soda together. Add the flour mixture, stir a few times to blend, then beat until just combined. Pour into the prepared pan and bake 50 to 60 minutes, or until a skewer inserted in the center comes out clean.

To make the pudding: Put the cream and sugar in a saucepan. Split the vanilla bean, scrape the seeds into the cream mixture, and add the pods. Add the salt. Bring the mixture just to a boil, then remove from the heat. Lift out the pods. Put the chocolate in a heatproof bowl and pour half the hot cream over it. Let it stand 30 seconds, then begin stirring gently with a spatula from the center out, combining the cream with the chocolate as it melts. Slowly stir in the remaining cream. When completely blended, let the mixture cool to lukewarm. Put the egg yolks in a large bowl and whisk gently to break up. Whisk in a large spoonful of the chocolate mixture to temper the eggs. Continue slowly adding the chocolate mixture, whisking constantly, until completely blended. Strain through a fine-meshed sieve.

Preheat the oven to 300 F. Spray 8 stainless 5-ounce timbale cups with vegetable oil spray and blot out the excess. Line the bottoms with circles of parchment paper.

Chop half the banana bread into large chunks, then process in a food processor until it turns to bread crumbs. Put the crumbs in a mixing bowl and repeat with the remaining half loaf. Add the finely-chopped chocolate to the crumbs. Stir the milk chocolate custard to the crumbs and chocolate, folding to just blend the mixture. Spoon into the prepared timbales. Place the timbales in a baking pan with high sides and pour hot water around them, two-thirds of the way up the sides. Bake until the tops puff, about 40 minutes; rotate the pan in the oven about half way through. Remove and cool completely.

To make the mint sauce: Put the mint leaves in water and bring just to a boil. Drain and plunge into ice water. Roughly chop the leaves. Pour enough corn syrup into a blender to cover the blades. Add the mint and process until very smooth. The mixture will become warm as it processes. Strain through a fine-meshed sieve. Cool the sauce on ice, then place in a squeeze bottle. Keep the bottle on ice before using.

To serve: Melt the chocolate in the top of a double boiler over barely simmering water. Fill a piping bag with a very small tip (or a plastic bag with one corner snipped to create a very small hole) with the melted chocolate and pipe a chocolate design on the plates; accent with drops of mint sauce. Run a sharp knife around the sides of the timbales to release the molds. Invert onto the decorated serving plates, and remove the paper from the bottoms. Hold a chocolate lattice with one side against the plate next to the timbale and place a scoop of chocolate sorbet on the bottom of the lattice to anchor it. Garnish with a chocolate panel. Repeat with all the plates.