Melt the chocolate over a double boiler.

Heat the cream with the sugar until the sugar dissolves and add the cream to the melted chocolate. Mix well until the cream is fully incorporated and leave to cool in the fridge while you bake the cake layers. Just before assembling the cake, take out the chocolate cream filling and whip whip for a few minutes until fluffy.

Preheat oven to 320 °F (160 °C).

In a food processor blend the walnuts and powdered sugar together (to prevent the walnuts from releasing their oil and becoming a walnut butter) and process until you have a very finely ground walnut meal

Using a hand mixer, beat the egg whites until foamy but not stiff (to prevent the cake from getting hard and crumbly)

Add the walnuts and sugar meal to the egg whites, add the flour, and mix lightly by hand.

Line the bottom and sides of an 8-inch cake form with parchment paper and brush it well with a neutral tasting oil like avocado, grape seed or sunflower oil

Pour 1/4 of the batter in the parchment lined cake form base, and spread out evenly until you get 2-3 mm thick layer. Bake the first layer for 10-12 min.

Repeat the above step 3 more times for a total of 4 cake layers.

Separate about 1/3 of the chocolate cream filling to use for covering the sides of the cake. Use the remaining cream to spread between the cake layers.

Place a cake layer at the bottom of your spring form, and cover liberally with chocolate cream.

Repeat the above step with the remaining 3 cake layers and finish with chocolate cream.

Use the 1/3 of the chocolate cream to cover the sides.

Place the cake in the fridge for a bit so the chocolate hardens.

Make the chocolate ganache:

Melt the chocolate over a double boiler then slowly add 1 tbs of oil and mix until the oil is incorporated. This will give the ganache its glossy look.

Once the cake cools, pour the ganache over the top and the sides, and garnish with chopped pistachios, or other nuts