Preheat oven to 300°F (150°C). Line a muffin tin with cupcake liners.
In a heatproof bowl, combine cream cheese, butter, and milk. Place over a simmering pot of water (double boiler) and whisk until smooth. Let cool slightly.
Whisk in egg yolks, vanilla, lemon zest, and sifted flour + cornstarch. Mix until smooth and lump-free.
In a separate clean bowl, beat egg whites with cream of tartar until foamy. Gradually add sugar and beat until soft peaks form (not stiff).
Gently fold the meringue into the yolk mixture in 3 batches. Be gentle to keep it fluffy.
Pour batter into cupcake liners (about ¾ full). Tap tray lightly to release air bubbles.
Place muffin tray in a larger baking pan. Pour hot water into the outer pan (water bath).
Bake at 300°F (150°C) for 25–30 minutes, then reduce to 265°F (130°C) for another 10–15 minutes.
Let cool in the oven with the door ajar to prevent shrinkage.
✨ Optional Toppings:
Dust with powdered sugar
Add a dollop of whipped cream
Top with fresh fruit or a berry compote
Would you like a version with chocolate or matcha next?
