Ingredients :

• Philadelphia-style cream cheese — This is what makes all the difference in texture. Kiri works, Saint-Morêt too. However, avoid low-fat versions — they make the cake rubbery and bland. Take it out of the fridge 30 minutes before starting; it should be soft to the touch.
• The 4 eggs — Room temperature is mandatory. Cold eggs = egg whites that don’t whip as well = a denser cake. Take them out at the same time as the cheese. Separate the whites from the yolks right at the start, before doing anything else.
• T45 Flour / All-purpose flour — The original recipe uses Italian type 00 flour, which is very fine. Regular T45 or all-purpose works exactly the same. What matters is sifting it — it takes 30 seconds and really changes the final lightness.
• Fresh lemon juice — Only one tablespoon, but it does two things at once: it balances the taste of the cheese (otherwise it can feel a bit heavy on the palate) and it helps the whites whip up. Use fresh, not bottled — the bottle has a preserved taste that you can detect in the cake.