Sift the cake flour, cocoa powder and baking powder. Bring the eggs back to room temperature and beat them. Break the chocolate and walnuts into small pieces.
Line the mold with parchment paper.
Bring the margarine back to room temperature, and cream it using a handheld mixer. Add granulated sugar in two separate additions, and mix until the sugar has dissolved and it becomes pale in color.
Add the eggs little by little, and mix well with each addition. Be careful not to let the mixture separate.
Microwave the chocolate for 2 minutes on a heatproof plate. If it has not melted throughly, stir with a spoon and it will melt with the remaining heat. Microwave the heavy cream for 20 seconds and mix it with the chocolate.
Add the chocolate from step 5 into the mixture from step 4 and beat together.
Sift the previously sifted powdered ingredients into the batter from step 6 and fold with a rubber spatula (be careful not to overwork the batter). Add walnuts and fold in quickly. Preheat the oven to 170°C.
Pour the batter into the mold and flatten the surface with a spatula. Bang it a couple of times onto the table from about 20cm high to get rid of the air bubbles. Bake at 170°C for 40 minutes.
Make a shallow incision in the middle of the cake about 20 minutes into the baking process, for a nice crack when finished baking.
Remove from the mold when baked, and wrap with plastic wrap when cooled. The cake tastes better the next day.
Story Behind this Recipe
My husband requested "Chocolate cake that's rich but not too sweet." I made 3 different cakes, and my husband said "this one is the best!"
The margarine and eggs might separate because there are more eggs. Please don't bother and add chocolate if they separate. You can keep it for a couple of days in the refrigerator, but since there is a lot of chocolate in the cake, it will be quite hard directly out of the refrigerator. Please bring the cake back to room temperature and enjoy.