In a double-boiler, combine the chocolate and butter, melt and keep warm.

In a separate double-boiler, combine the egg yolks and granulated sugar (A). Heat until warm to the touch.

When the egg mixture has warmed up, remove from the double-boiler and beat until fluffy and the color becomes whitish. You can use the same warm water (double-boiler) from Step 5 by replacing the bowls.

Combine Step 5 into 7 and mix it really well.

Pour heavy whiping cream into the batter and mix more.

Add the sifted dry ingredients and mix it even more.

Mix the batter really well.

In a separate bowl, combine the chilled egg whites and 1/3 of the granulated sugar (B) and start beating.

Add remaining granulated sugar 1/3 at a time. Beat to a meringue or until stiff peaks form.

With a spatula, fold the meringue into Step 11 in three batches.

Fold until the batter becomes shiny.

Pour the batter into the pan and even out the top. Bake 20-30 minutes at 180℃.

20 minutes later, insert a skewer into a center of the cake. If it comes out with just a small amount of cake stuck to it, it is done. Be careful, it is over-baked if it comes out dry!

Take the cake out of the pan, remove the parchment paper and let it cool. When the cake is completely cool, wrap it with plastic wrap and refrigerate. When it cools down, the center will deflate.

Serve with whipping cream for an even better taste.