Ingredients :

• Unsweetened cocoa — This is what decides the character of the cake. Use Van Houten or Valrhona if you want something truly intense. Basic supermarket cocoa works, but the result will be flatter in taste. 40g is the dose that gives depth without tipping into bitterness.
• The eggs — Three whole eggs, at room temperature — they rise better than cold eggs. And really whisk them for at least 3-4 minutes: that’s what makes the cake swell, not the baking powder alone. Eggs are the engine of this recipe.
• Oil or butter? — The recipe offers both, but for an everyday cake that lasts, sunflower oil wins. It retains moisture in the crumb much longer than butter. Butter gives more flavor, but the cake starts to dry out by the next day.
• Baking powder — A full packet, sifted with the flour. If it forms lumps in the batter, you’ll have uneven rising spots and the cake won’t rise uniformly. 10 seconds of sifting avoids this kind of surprise.