- Preheat Oven:
- Preheat your oven to 325°F (160°C). Line the bottom of a 8-inch (20cm) round cake pan with parchment paper.
- Melt Cheese and Butter:
- In a heatproof bowl, melt the cream cheese, butter, and milk together. You can do this over a double boiler or in the microwave. Once melted, let it cool slightly.
- Sift Dry Ingredients:
- In a separate bowl, sift together the all-purpose flour and cornstarch. Set aside.
- Add Egg Yolks:
- Add the egg yolks to the cream cheese mixture one at a time, mixing well after each addition. Stir in the sifted dry ingredients and lemon zest (if using) until smooth.
- Whip Egg Whites:
- In a clean, dry bowl, whip the egg whites and cream of tartar until soft peaks form. Gradually add sugar and continue whipping until stiff peaks form.
- Fold Egg Whites:
- Gently fold the whipped egg whites into the cream cheese mixture in three additions until well combined.
- Pour Batter:
- Pour the batter into the prepared cake pan. Tap the pan on the counter to remove any air bubbles.
- Bake:
- Place the cake pan in a larger pan filled with hot water (water bath) to create steam. Bake in the preheated oven for about 60-70 minutes or until the top is golden brown and the cake springs back when lightly touched.
- Cool:
- Allow the cake to cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely.
- Dust with Powdered Sugar:
- Once cooled, dust the top with powdered sugar before serving.
Enjoy your light and airy Japanese Cotton Cheesecake! Adjust the baking time based on your oven, and make sure to check for doneness with a toothpick.