Chocolate Truffle Cake

INGREDIENTS
200 Gr. Semi-Sweet Chocolate – I use 75% cocoa bittersweet chocolate
200 Gr. Melted Butter
4 Egg yolks
200 Gr. Caster Sugar
4 Egg whites with a dash of salt and cream of tartar
70 Gr. All purpose flour

INSTRUCTIONS
In a small bowl, melt the chocolate and butter in a microwave for two minutes. I use medium power to melt the two ingredients, to avoid burning. Mix well and let the ingredients cool at room temperature for a few minutes.
In a separate bowl, using a hand whisk or hand mixer, combine the egg yolks and sugar and whisk until pale yellow in color and the mixture starts to thicken; about 3-4 minutes.
In a separate bowl, mix the egg whites with a dash of salt and cream of tartar which allows the whites to hold their shape. Mix until medium peaks; which means the egg whites hold their shape and you can see trace of the beaters in the mixture.
Now, for the assembly, pour the chocolate-butter mixture in the egg yolks and sugar preparation and using a spatula, fold the two together, until you have a homogenous mixture. Add the flour, which you can sift right over the chocolate-egg mixture and fold it with a spatula.
Add the egg whites in 3-4 additions, again using a spatula and being careful not to deflate the preparation.
Bake in a 160 Celsius oven for 30-35 minutes. The cake will puff up considerably and will eventually deflate a little bit.
Dust with powder sugar and serve at room temperature with a few raspberries.