I love making semifreddo. It's like a delicious frozen mousse. You can make all the components in advance so it is great for a dinner party where you don't want to be leaving your guests alone to prepare dessert. This recipe does make a lot of semifreddo but you can put the extra in the freezer and it lasts a few months. —singing_baker
Put hazelnuts in a food processor and pulse until finely ground. Do not make a paste. Whisk heavy cream, espresso powder and confectioners sugar in the bowl of an electric mixer until stiff peaks form. Put in fridge until ready to use
In a separate clean bowl whisk egg whites until foamy. Add sugar gradually until stiff peaks form. Add in vanilla. Gently fold egg white mixture into whipped cream. Fold in mini chips and ground hazelnuts. Put into a glass container, cover and put in freezer until firm. About 4 hours.
Profiteroles and chocolate sauce
Preheat oven to 350 degrees. In a small saucepan over medium high heat combine butter, water, sugar and salt until butter is melted. Take mixture off of heat and whisk in flour. Place back on heat and whisk until mixture comes together.
Put mixture in a standing mixture with the paddle attachment. Beat until slightly cooled. Add eggs and egg white one at a time until mixture is no longer lumpy. Put mixture in a piping bag with a large round tip. Pipe 1 1/2 inch rounds about 2 inches apart on a parchment lined baking sheet. Bake for about 25 minutes until golden and puffed.
make chocolate sauce: combine corn syrup and chocolate in a small saucepan over medium heat. Whisk until melted take off heat and whisk in heavy cream.
To assemble cut profiteroles in half horizontally. Put a Big scoop of semifreddo in between the two halves and pour chocolate sauce on top.