MILK CHOCOLATE MOUSSE

Steps:

• Line a baking sheet with parchment and put eight 3-inch tart rings on it.
• Whisk the butter and cocoa powder together until smooth.
• Lay a sheet of phyllo on your work surface and brush it with the chocolate butter. Sprinkle with 1 tablespoon of the hazelnut flour. Cover with another sheet of phyllo, brush with chocolate butter, and sprinkle with another tablespoon of the hazelnut flour. Cover with another sheet of phyllo and brush with chocolate butter. Roll the phyllo with a rolling pin to compress the layers. Cut out 4 rounds with a 4-inch cutter and line four of the tart rings with the phyllo. Take your time doing this so you make tight corners and don't crack the phyllo. Repeat with the remaining 3 sheets of phyllo. Freeze the shells, on the baking sheet, for at least 1 hour or, well wrapped, for up to 1 month. The freezing helps guarantee that the shells won't slump when you bake them.
• Heat the oven to 375°F or 350°F on convection. Line the pastry with parchment and fill with dried beans (or rice or pastry weights). Bake the shells until crisp, about 12 minutes. Lift the parchment and beans out right away and let the shells cool completely on a rack. Lift off the rings when you're ready to put the dessert together.
• Line a 9 x 12-inch rimmed baking sheet with parchment.
• Melt the chocolate in a glass bowl in the microwave in 30-second spurts, or melt in a double boiler. After each spurt, let the chocolate sit for a minute or so, then stir it with a heatproof rubber scraper. Let the chocolate cool to 120° to 115°F. The temperature is important here. If the chocolate is too hot or too cold, the mousse will be grainy or sludgy.
• Meanwhile, pour the cream into the bowl of a standing mixer fitted with the whisk. Whisk on medium speed to very soft peaks. You want the cream to hold a loose shape.
• Scrape the chocolate into a large wide bowl and pour in all the cream. Fold together quickly, spinning the bowl as you fold, and keeping the mousse light and frothy.
• Pour the mousse into the baking sheet and spread it out evenly with an offset spatula. Freeze for about 20 minutes.
• Lay a piece of parchment on top of the mousse. Set another baking sheet on top. Holding the two sheets together, invert. Lift up the top sheet and peel away the original parchment. Cut out 3-inch rounds of the mousse and return the sheet to the freezer for another 20 to 30 minutes, to set the mousse completely and make sure the rounds have nice clean edges before you try to lift them. Once the mousse has set, you can transfer the rounds to a tray with an offset spatula and refrigerate until you're ready to serve or for up to 2 days.
• Heat the oven to 375°F or 350°F on convection.
• Set the chocolate phyllo shells on a baking sheet. Fill each with a couple of tablespoons of hazelnut caramel sauce. Add two banana halves, trimming them so they fit, to the shell. Slide the baking sheet into the oven and heat through, until warm to the touch, about 5 minutes.
• Transfer the shells to dessert plates, top each with a round of mousse, and serve. If you want, you can dust the mousse with cocoa powder, drizzle the plate with the caramel from the bananas, spoon on more hazelnut caramel, or spoon on some chocolate sauce.
• You can replace the chocolate mousse with ice cream. Let the ice cream soften, then pack it into 3-inch ring molds set on a baking sheet lined with parchment. Even off the tops with a spatula and refreeze the ice cream. Fill the phyllo right before serving. Instead of making the Hazelnut Caramel Sauce, warm up some store-bought caramel sauce and fold in toasted hazelnuts. Or fold in honey-roasted peanuts, cashews, or pecans. But don't forget the salt.