1Melt the chocolate and butter over a double boiler until melted. Allow to cool.
2Melt the chocolate and butter over a double boiler until melted. Allow to cool.
3Melt the chocolate and butter over a double boiler until melted. Allow to cool.
4Separate 4 eggs. Whisk 2 whole eggs and 4 egg yolks with 100g of sugar until combined.
5Separate 4 eggs. Whisk 2 whole eggs and 4 egg yolks with 100g of sugar until combined.
6Separate 4 eggs. Whisk 2 whole eggs and 4 egg yolks with 100g of sugar until combined.
7Slowly whisk in the warm chocolate mixture.
8Slowly whisk in the warm chocolate mixture.
9Slowly whisk in the warm chocolate mixture.
10Beat the 4 egg whites with a handheld mixer until foamy (about 2 minutes).
11Beat the 4 egg whites with a handheld mixer until foamy (about 2 minutes).
12Beat the 4 egg whites with a handheld mixer until foamy (about 2 minutes).
13Gradually add the remaining 100g of sugar and beat until soft peaks form (about 5 more minutes).
14Gradually add the remaining 100g of sugar and beat until soft peaks form (about 5 more minutes).
15Gradually add the remaining 100g of sugar and beat until soft peaks form (about 5 more minutes).
16Gently fold about a quarter of the beaten egg whites into the chocolate mixture to lighten it, then gently fold in the remaining whites.
17Gently fold about a quarter of the beaten egg whites into the chocolate mixture to lighten it, then gently fold in the remaining whites.
18Gently fold about a quarter of the beaten egg whites into the chocolate mixture to lighten it, then gently fold in the remaining whites.
19Scrape the batter into the pan and smooth the top. Set the pan on a rimmed baking sheet and bake at 175C until the top is puffed and cracked and the center is no longer wobbly (35 to 40 minutes).
20Scrape the batter into the pan and smooth the top. Set the pan on a rimmed baking sheet and bake at 175C until the top is puffed and cracked and the center is no longer wobbly (35 to 40 minutes).
21Scrape the batter into the pan and smooth the top. Set the pan on a rimmed baking sheet and bake at 175C until the top is puffed and cracked and the center is no longer wobbly (35 to 40 minutes).
22Let the cake cool in the pan on a rack. The center will sink as it cools.
23Let the cake cool in the pan on a rack. The center will sink as it cools.
24Let the cake cool in the pan on a rack. The center will sink as it cools.