Step 1

Break up the chocolate and melt it in a bain-marie along with the butter.

Step 2

Separate the egg yolks and whites. Beat the egg yolks with 1/3 cup of sugar until they are very foamy. Beat the egg whites separately along with the remaining sugar. Using a spatula, gradually fold the beaten egg yolks and whites into the melted chocolate, alternating between them and making a continuous upwards circular movement.

Step 3

Line a round cake pan with parchment paper and butter the paper. Pour the batter into the pan and bake at 340°F in a convection oven for 30-35 minutes.