Prep. time: A few minutes
Cooking time: 45-50 minutes
Cooling time: 1 hour

A cake as soft and airy as a cloud. It's proof that you can make a big impression with just a few ingredients. Fresh orange zest adds a delicate aroma that I truly appreciate, but you can omit it if you're a die-hard chocolate lover. You'll still reach seventh heaven!

Step 1
Preheat the oven to 180°C / 350°F and place the rack in the center.

Grease a 22 cm / 9 in springform pan and line the bottom with parchment paper.

Step 2
In a microwave-safe bowl, add the chocolate chips and oil; heat for 1 minute. Stir and heat for another 20 seconds if the chocolate chips are not completely melted. Let cool slightly.

Step 3
In a separate bowl, using an electric mixer, beat the egg whites for about 1-1/2 minutes until soft peaks form.

Add ¼ cup of sugar and beat again for 1-1/2 minutes, until firm peaks form. Set aside.

In a large bowl, still using an electric mixer, beat the egg yolks with the remaining 12 tbsp of sugar and vanilla for about 2 minutes, until the mixture becomes pale and thick.

Step 4
Using the mixer, blend in the melted and slightly cooled chocolate, as well as the orange zest if desired, into the egg yolk mixture.

With a spatula, very gently fold in the beaten egg whites in three additions.

Step 5
Pour the batter into the pan and bake for 35 to 40 minutes max. (The center of the cake should be set but still slightly wobbly; it should not be fully cooked. The batter will rise significantly during baking and then settle back down after cooling—the top will crack as it cools, which is completely normal!)

Let cool for 1 hour before unmolding. Using a fine sieve, dust cocoa powder over the top of the cake and garnish with a little orange zest, if desired.