Preheat your oven to 350 degrees. Prepare and 8 inch cake pan with cooking spray or butter and flour if desired. Set aside.
Melt chocolate in the top of a double boiler set over simmering water or a heavy bottomed saucepan, over low heat.
Add butter and stir.
When the butter is melted, add ground almonds. Stir to combine. Remove from heat and set aside.
In a large mixing bowl combine the eggs, yolks, ¾ cup of sugar and cocoa powder. Whisk until totally incorporated.
Using a spatula scrape chocolate mixture into egg mixture and stir until blended. Set aside.
Using an electric mixer beat egg whites and salt until stiff peaks form, between 3 and 5 minutes.
Add remaining 1 tablespoon sugar and vanilla and beat to combine.
Gently fold the egg whites into the chocolate almond mixture.
Pour and scrape the batter into your prepared pan. Bake for between 25 and 29 minutes or a toothpick inserted into the center comes out clean
Remove from oven and allow the cake to cool in the pan for at least 5 minutes, if not 10, before placing the cake on a rack to cool completely.