1 cup of finely ground almonds - sliced toasted almonds in the food processor
4 big eggs
7 ounces semi sweet or bittersweet chocolate, chopped
11 tablespoons no salt butter, cut into small pieces
3/4 cup granulated white sugar, divided
1/2 tea spoon of pure vanilla extract
1/4 tea spoon of cream of tartar
Preheat the oven to 350 degrees F and place oven rack in the middle of the oven.
Place the sliced or blanched almonds on a baking sheet and toast in the oven for about 5 minutes or until lightly browned and fragrant.
Remove from oven and let cool.
Once completely cooled, place the nuts in a blender or small food processor and process until finely ground.
Almonds need to be at room temperature before grinding to prevent them from clumping.
If you find the almonds still clump when you ground them, add about 1 tablespoon of the sugar from the recipe.
The sugar will help prevent clumping as it absorbs any oil exuded from the almonds.
Increase the oven temperature to 375 degrees F and line an 8 inch springform pan with parchment paper.
Separate the cold eggs, placing the egg yolks in one bowl and the egg whites in another.
Cover with plastic wrap and let stand until they reach room temperature for about 30 minutes.
Melt the chopped chocolate and butter in a stainless steel bowl placed over a saucepan of simmering water.
Once melted, remove from heat.
Meanwhile place the egg yolks and 1/2 cup (100 grams) granulated white sugar in the bowl of your electric mixer, fitted with the paddle attachment.
Beat the yolks and sugar until pale and thick,about 3 minutes.
Beat in the melted chocolate mixture and vanilla extract.
Fold in the ground almonds.
In a clean bowl, place the egg whites and whisk until foamy.
Add the cream of tartar and continue whisking until soft peaks form.
Gradually sprinkle in the remaining 1/4 cup (50 grams) sugar and whisk until stiff peak forms.
Fold about 1/4 of the whites into the chocolate batter to lighten it.
Quickly fold in the rest of the whites and mix only until incorporated.
Pour the batter into the prepared pan and bake for 45 minutes or until a toothpick inserted in the center of the cake has a few moist crumbs.
Remove from oven and cool on a wire rack.
The cake will rise during baking but falls during cooling, leaving a crisp and cracked crust.
Once cool, run a spatula around the inside of the pan before releasing the sides.
If not serving immediately, cover and place in the refrigerator.
Serve cold or at room temperature.
Dust with powdered (icing or confectioners) sugar.