8 ounces white chocolate, chopped
8 ounces cream cheese, at room temperature
8 tablespoons (112 g) unsalted butter, at room temperature
1/2 cup (100 g) granulated sugar
1/4 teaspoon kosher salt
2 teaspoons pure vanilla extract (with vanilla seeds, if possible)
4 eggs (200 g, weighed out of shell) at room temperature, beaten
Whipped cream and berries, for serving (optional)
Preheat your oven to 325°F. Grease a 9-inch springform pan with nonstick cooking spray. Line the bottom of the pan with a 9-inch round of parchment paper. If using a water bath, cover the bottom and sides of the pan tightly with heavy-duty aluminum foil. Set the pan aside.
In a small, heat-safe bowl, place the chopped white chocolate. Melt either in the microwave (90 seconds at 50% power, and then for 30 seconds at a time at 50% power, stirring in between until melted and smooth) or over a double boiler (position the bowl over barely simmering water and stir occasionally until melted and smooth). Set the melted chocolate aside to cool while you prepare the other ingredients.
In the bowl of a stand mixer fitted with the whisk attachment or a large bowl with a handheld mixer, place the cream cheese, butter, sugar, salt, and vanilla. Whip on medium speed and then on high speed until light and fluffy (about 5 minutes). Lower the speed of the mixer to medium-low, and add the eggs one at a time. Increase the mixer speed to medium-high and continue to whip until well-combined (about 2 minutes). Reduce the speed again to medium-low, and drizzle in the melted white chocolate. Increase the speed to high and continue to whip for at least 5 minutes or until the mixture is smooth, but fluffy. The whisk should leave a visible trail in the batter.
Transfer the batter to the prepared springform pan and smooth into an even layer with an offset spatula. If using a water bath, place the pan in the center of a large roasting tin and place the pans in the center of the preheated oven. Pour hot water into the roasting pan while the pan is already in the oven (it’s much easier to move a pan around that doesn’t have hot water in it!) until the water reaches about halfway up the sides of the springform pan. Bake until the top is lightly golden brown and the cake doesn’t jiggle more than very slightly when moved from side to side. That will take about 45 minutes if you’re using a water bath, and about 5 to 10 minutes less without a water bath.
Turn off the oven and prop the door open slightly. Allow the cake to cool in the oven for at least 15 minutes and up to an hour. Remove the cake from the oven, allow it to cool in the pan to room temperature, and then place in the refrigerator for at least an hour, or up to 3 days. Run a knife around the edge of the pan to ensure that the edges aren’t sticking before unmolding the chilled cake. Rinse a large knife under hot water, then dry it off before making each cut in the cake. The knife should glide right through the cake. Garnish with whipped cream and berries, and serve chilled.