Line the bottom of a 9-inch springform pan with a circle of parchment paper. Grease both the sides and the parchment with cooking spray or evoo. Line a baking sheet with parchment paper. Preheat oven to 350°F.

Toast hazelnuts on prepared sheet until golden. Transfer nuts to a clean kitchen towel. Rub nuts in the towel to loosen skins. Reduce oven temperature to 325°F. 

Transfer nuts to food processor with potato starch and quarter cup sugar. Pulse to grind nuts, or stir together ground nuts if using ground nuts.

Melt chocolate with salt in double boiler. Add evoo and cool slightly.

Whisk in egg yolks, vanilla bean essence, and nut mixture.

Whip whites to soft peaks. Slowly add remaining quarter cup sugar, with machine running, until glossy peaks form.

Fold whites into chocolate mixture and pour batter into prepared pan. Bake at 325°F for 30 to 40 minutes or until a toothpick inserted comes out clean. 

Cool completely before unmolding. Run a knife around the edge before removing from pan.

Stir melted chocolate and wine together to form a pourable glaze.

Pour glaze over cooled cake, allowing the glaze to drip down the sides. 

Allow glaze to set up before garnishing cake with grated chocolate.

Shaved Chocolate: 

Grate chocolate using a microplane or vegetable peeler over top of the cake.