Preheat your oven to 320°F (160°C). We’re going to use a water bath, so get a roasting pan ready and boil some water. You'll also need a 6-inch springform pan. Line the bottom of the pan with parchment paper. Don't grease the sides – this helps the cheesecake climb up nicely.

In a large bowl, beat the softened cream cheese with 1/4 cup of sugar until it’s smooth and creamy. You can use a hand mixer or a stand mixer. Make sure there are no lumps.

In a small saucepan, melt the butter over low heat. Once melted, add the milk and stir to combine. Heat until it’s just warm, but not boiling.

Slowly pour the warm milk mixture into the cream cheese mixture, mixing on low speed. Add the egg yolks, one at a time, mixing well after each addition. Stir in the lemon juice. The batter should be smooth and liquidy.

Sift together the cake flour and cornstarch into a separate bowl. Gradually add the sifted flour mixture to the cream cheese batter, mixing on low speed until just combined. Be careful not to overmix – we want to keep the batter light.

In a clean, grease-free bowl, beat the egg whites with a pinch of salt until soft peaks form. Gradually add the remaining 1/4 cup of sugar, a little at a time, and continue to beat until stiff, glossy peaks form. This meringue is what makes the cheesecake fluffy!

Gently fold about one-third of the meringue into the cream cheese batter to lighten it. Then, gently fold in the remaining meringue in two additions, until just combined. Be careful not to deflate the meringue – fold gently!

Pour the batter into the prepared springform pan. Place the pan inside the roasting pan. Carefully pour the boiling water into the roasting pan until it comes about halfway up the sides of the springform pan.

Bake in the preheated oven for 60-70 minutes, or until the top is lightly golden and the cheesecake is set around the edges but still slightly jiggly in the center.

Turn off the oven and leave the oven door slightly ajar. Let the cheesecake cool in the oven for 30 minutes. Then, remove the roasting pan from the oven and let the cheesecake cool completely at room temperature. Finally, refrigerate for at least 4 hours, or preferably overnight, to chill completely and set.

Once chilled, gently remove the cheesecake from the springform pan. Dust with powdered sugar, if desired, and get ready to enjoy your amazing Japanese Fluffy Cheesecake!