For The Cake, Place A Rack In The Center Of The Oven, And Preheat The Oven To 375°F.
Lightly Grease The Bottom And Sides Of A 10″ Springform Pan With Butter.
Line The Bottom Of The Pan With A Circle Of Parchment Paper.
Grease The Parchment Paper, And Dust With Flour.
Shake Out The Excess Flour, And Set The Pan Aside.
2.
Place The Reserved, Cooled, Blanched Hazelnuts In A Food Processor Fitted With A Steel Blade.
Pulse Until The Nuts Resemble Coarse Meal, About 1 Minute.
They Will Be A Little Sticky.
Set Aside.
3.
Place The Butter And Honey In A Large Mixing Bowl, And Beat With An Electric Mixer On Medium Speed Until Smooth And Creamy, 1 Minute.
Add The Egg Yolks, 2 At A Time, And Blend Until Each Round Of Egg Yolks Is Incorporated.
Scrape Down The Bowl With A Rubber Spatula, And Fold In The Ground Hazelnuts.
Set Aside.
4.
Put The Chocolate In A Medium-Size Glass Bowl, And Place In The Microwave On The Defrost Setting For 3 Minutes, Stirring Until The Chocolate Has Melted.
Cool A Few Minutes, Stirring, And Then Fold Into The Batter.
Beat On Medium Speed Until Blended.
Set Aside.
5.
Place The Egg Whites And Salt In A Large Bowl, And Beat With Clean Beaters On High Speed Until Nearly Stiff Peaks Form, 4 Minutes.
Fold The Whites Into The Batter In 3 Portions, Folding Just Until Combined.
Turn The Batter Into The Prepared Pan, And Place The Pan In The Oven.
6.
Bake The Cake For 20 Minutes.
Then Reduce The Oven Temperature To 350°F And Bake Until The Cake Has Welled In The Center And A Toothpick Inserted In The Center Comes Out Clean, 32 To 37 Minutes.
Remove The Pan From The Oven, And Place On A Rack To Cool For 20 Minutes.
7.
While The Cake Bakes, Prepare The Frosting.
Place The Cream In A Small Saucepan Over Medium Heat Until It Nearly Boils, About 2 Minutes.
Place The Chopped Chocolate In A Large Bowl.
Pour The Hot Cream Over The Chocolate And Stir With A Wooden Spoon Until The Chocolate Melts And The Frosting Is Smooth.
Let The Frosting Cool To Room Temperature.
It Will Thicken As It Cools.
8.
Run A Knife Around The Edges Of The Cake.
Unfasten The Collar Of The Springform Pan, And Remove The Bottom And The Parchment Paper From The Bottom Of The Cake.
Place The Cake On A Serving Platter.
Level The Top Of The Cake With A Long Serrated Knife.
Flip The Cake So It Is Bottom Up.
Spread The Top And Sides Of The Cake With The Frosting.
Garnish With Chocolate Shavings.
Let The Cake Rest For 30 Minutes, Then Slice And Serve.
