Preheat your oven to 300°F (150°C) and line an 8-inch round cake pan with parchment paper. Place this pan inside a larger baking dish for the bain-marie.

In a heat-proof bowl, combine cream cheese, unsalted butter, and heavy cream over simmering water. Stir until smooth and melted, about 5 minutes. Remove from heat and mix in the egg yolks, sifted cake flour, lemon zest, and vanilla extract, then let cool for 10 minutes.

Beat egg whites with lemon juice until frothy. Gradually add granulated sugar until medium-soft peaks form. The meringue should be glossy and hold a soft 'J' shape.

Gently fold one-third of the meringue into the cooled cream cheese mixture. Continue incorporating the remaining meringue in two more additions to maintain airiness.

Pour the batter into the prepared cake pan, tap gently on the counter, and place it in the larger baking dish. Pour hot water into the dish, up to halfway of the pan. Bake for 80-90 minutes until golden brown and a toothpick comes out clean.

Turn off the oven and let the cheesecake cool inside for 30 minutes. Rotate the pan for even cooling before transferring to a wire rack and cool completely for another hour.

Enjoy the cheesecake warm or chilled. For richer flavor, refrigerate for at least an hour before serving. Slice and top with powdered sugar, apricot jam, or fresh berries.