Preheat your oven to 300°F (150°C). Line a muffin pan with 10 paper cupcake liners. For extra lift and even baking, use high-quality liners and a sturdy muffin pan.

In a heatproof bowl set over a pot of simmering water (double boiler method), melt the cream cheese, butter, and milk. Stir constantly until the mixture is smooth and silky. Remove from heat and let cool for a few minutes before adding dry ingredients.

Sift the cake flour and cornstarch together to eliminate any lumps. Gently whisk into the cream cheese mixture until fully incorporated and smooth.

Add the egg yolks one at a time, whisking until the mixture is creamy and uniform. This step helps create the rich yet light structure of the cupcakes.

In a clean, grease-free bowl, beat the egg whites and cream of tartar until foamy. Gradually add the sugar and continue to beat until stiff peaks form. The whites should be glossy and hold their shape.

Carefully fold the meringue into the cream cheese mixture in three additions. Use a gentle, sweeping motion to avoid deflating the batter. The goal is to keep the mixture airy and light.

Spoon the batter into the prepared cupcake liners, filling each about ¾ full. Place the muffin pan inside a larger baking dish. Fill the outer dish with hot water about halfway up the sides of the muffin pan. This gentle steam helps prevent cracking and creates that cottony texture.

Bake for 25–30 minutes or until the tops are a light golden color and the centers are set. Avoid opening the oven door too often to maintain the temperature. When done, turn off the oven and let the cupcakes sit inside for 5 more minutes with the door ajar.

Let the cupcakes cool completely on a wire rack. Once cooled, you can pipe whipped cream into the center for a creamy surprise. Finish with a light dusting of powdered sugar for that classic, elegant look.