Line 3 large baking sheets with parchment or silicone paper. On each sheet, trace a 9-inch circle. Turn paper over so that you can see the tracings. Preheat oven to 225 degrees.
Mix together 1 cup sugar, finely chopped nuts, and sifted cornstarch. Place egg whites in bowl of electric mixer. Using the whip attachment, start whipping at slow speed until whites are foamy, add the cream of tartar and salt, continue whipping at fast speed until soft peaks form. Gradually add the 3 tablespoons of sugar and continue whipping until stiff peaks form. Add the vanilla extract. Remove bowl from mixer stand, fold in the nut mixture by hand, a small amount at a time. Divide mixture between 3 circles and spread into even layers. Bake for approximately 45 minutes to 1 hour or until meringues are lightly coloured and dry.
Place the 3 meringue layers on work surface, turn 1 layer over to the smooth side (for top layer). Spread a very thin layer of caramel sauce on top layer and chill. Lay 2 remaining meringues on work surface and brush with melted milk chocolate. Chill until set.
Remove all layers from refrigerator and place the bottom layer on serving plate, spread 1/2 of the toffee cream over the first layer, place next layer on top and spread the remaining 1/2 of the toffee cream over layer. Place top layer gently on top. Fill a piping bag with a 1/2-inch plain tip and pipe 8 rosettes around the outside border of the layer, leaving space between the rosettes. Fill the spaces with broken pieces of toffee. Drizzle caramel lightly over the whipped cream rosettes. Chill 4 hours before serving.
In a small saucepan, scald the cream and set aside. Combine the sugar with 1/2 cup water in a large saucepan. Stir to moisten the sugar. Bring to a simmer, swirling the pan gently to dissolve the sugar. Increase heat and continuing simmering without stirring until syrup begins to color. Once the syrup turns a deep amber or caramel color, remove from heat and add the cream in a steady stream, stirring with a wire whisk. Caramel and cream will bubble up and steam, but keep stirring and continue to whisk until caramel is completely dissolved and combined with the cream. Stir in pieces of butter until melted and combined. Stir in vanilla and salt. Set aside to cool.
Hazelnut Toffee Crunch:
Coat a cookie sheet with vegetable oil and set aside. Preheat oven to 200 degrees F. Place the sugar, water, corn syrup and vanilla in a heavy-bottomed saucepan and stir well to dissolve the sugar. Cook the mixture over high heat until it reaches a boil. Let the mixture boil for 1 minute. Add the butter, stirring to combine. Continue to boil, stirring often. Scrape the bottom of the pan to keep the mixture from burning. The mixture should reach 290 degrees on a candy thermometer and is a deep golden brown. Remove from the heat and stir in the nuts. Turn the mixture out onto the oiled tray and let it cool completely.
Whipped Cream Filling:
Whip the cream until soft peaks form, add the icing sugar; continue whipping until stiff peaks form. Set aside 1 cup of cream for decoration. Fold the toffee into the remaining cream.
Remaining caramel sauce can be refrigerated for up to 3 weeks to be used for any number of uses. Remaining toffee can be stored at room temperature in an airtight container for several weeks.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.