Prepare walnut cake. Preheat oven to 325F (160C). Grease and line with parchment paper a 8 ½ inch (21cm) pan.
Separate egg whites from the yolks. Add a pinch of salt over the whites and start mixing until foamy. Gradually add sugar and mix until stiff peaks form.
Gently fold in ground walnuts and flour. Pour the batter into the prepared pan and bake for 25-30 minutes.
Let it cool completely and use a 8 inch (20cm) cake ring to cut the edges of the cake. Transfer the cake into a 8 inch (20cm) springform pan, lined with parchment paper.
Prepare the chocolate layer. Place the chocolate and cream into a heatproof bowl and melt over bain-marie. Spread the melted chocolate evenly over the walnut cake and refrigerate to set.
Meanwhile prepare the caramel walnut layer. Toast the walnuts in a pan stirring constantly. When cooled enough cut in smaller pieces.
In a small bowl mix the yolks with the 3 tbsp (45g) of sugar until creamy and light yellow colored.
Place the 1/3 cup (70g) sugar with water into a saucepan. Place over medium-low heat until sugar dissolves and gets a caramel color.
Add butter, stir until melted and then add walnuts and salt. Add mixed yolks and continue mixing just until it thickens, up to 1 minute. Don’t overcook Cool slightly.
Spread the walnut caramel layer over the chocolate and refrigerate until the mascarpone mousse is prepared.
Prepare mascarpone mousse. Dissolve gelatin in cold water, add instant coffee and let it swell for about 5 to 10 minutes.
In a large bowl mix mascarpone until smooth. Add powdered sugar and mix to combine. Add vanilla extract. Place the gelatin over low heat just until the gelatin dissolves and pour it over the mascarpone mixture and mix to combine.
In another bowl mix cream until stiff peaks form. Gently fold the cream into mascarpone mixture.
Place the walnut cake in the center of a 9 inch (23cm) parchment paper lined pan or cakeware from Delicake
, as I’ve used.
Spread the mousse on top and edges of the cake. Cover and freeze for at least 4 hours or overnight.
Prepare caramel mirror glaze. Dissolve gelatin in 1/4 cup cold water and let it swell for about 5 to 10 minutes.
In a small bowl dissolve cornstarch in 1 tbsp water and set aside until ready to use.
Place sugar and lemon juice in a saucepan. Place over medium low heat until sugar dissolves and gets a caramel color. Add water, cream, dissolved cornstarch and salt. Bring to a boil until thickens.
Remove from heat, add gelatin and stir to combine.Sieve the glaze and let it cool to 85F (29C).
Take the cake out of the freezer and use a hair dryer to defrost the edges. Remove the cake from the pan and place it over a rack or simply on a bowl placed over a parchment paper lined baking sheet to collect the excess.
Pour the glaze on top and edges of the cake. Use an offset spatula to remove the drips and decorate the bottom of the cake with chopped walnuts. Transfer the cake to a serving platter and refrigerate for several hours to defrost the cake and set the glaze.
Prepare chocolate flower. Use about two 5×15 inch (12x38cm) hard paper pieces and curve. Melt the 2.5 oz (70g) semisweet chocolate over bain marie. Remove from heat and add 1 oz (30g) of chocolate for tempering.
Brush the chocolate on parchment paper in shape of flower petals. Make about seven or eight 4 inch (10cm) petals and about 8 smaller 2 inch (4cm) petals. Place the parchment paper over the prepared curved hard paper and refrigerate the petals for about 10 minutes, remove and peel from the parchment paper.
Assemble the flower. On a parchment paper add a pit of melted chocolate and arrange the large petals. Add more melted chocolate and arrange the smaller petals. Add melted chocolate in the center and add chopped nuts. Refrigerate the flower for at least 15 minutes before decorating the cake. Slightly brush golden powder on the leaves if desired. Enjoy.