1. Prepare the Cream Cheese Mixture:
   • Melt butter with milk over low heat and let cool.
   • Beat softened cream cheese until smooth. Gradually add the melted butter and milk mixture.
   • Stir in vanilla and egg yolks, adding one at a time.
2. Combine Dry Ingredients:
   • Sift cake flour, cornstarch, and salt into a bowl.
   • Gently fold these dry ingredients into the cream cheese mixture.
3. Beat the Egg Whites:
   • Whisk egg whites until frothy, add cream of tartar, and beat until soft peaks form.
   • Gradually add sugar and whisk until stiff peaks are glossy.
4. Fold the Egg Whites:
   • Fold the beaten egg whites into the cream cheese mixture in three batches to keep the batter airy.
5. Bake the Cheesecake:
   • Pour batter into a prepared 8-inch round cake pan. Place it in a baking dish with hot water for a water bath.
   • Bake at 320°F (160°C) for 50-60 minutes until golden and a toothpick comes out clean.
6. Cool the Cheesecake:
   • Turn off the oven and let the cheesecake cool inside with the door slightly open for 15 minutes.
   • Then, cool it completely before removing from the pan.
7. Serve:
   • Dust with powdered sugar if desired and enjoy the fluffy texture.

Tips:

• Ensure ingredients are at room temperature for a smooth batter.
• Beat egg whites to stiff peaks but don’t over-whip.
• Use a water bath for a moist, fluffy texture.

Variations:

• Lemon Cheesecake: Add lemon zest and juice.
• Matcha Cheesecake: Blend in matcha powder for a green tea flavor.

This cotton cheesecake offers a cloud-like texture, perfect for a delicate and elegant dessert.