Instructions

1. Heat the oven to 350°F. Coat a 9-inch springform pan, preferably nonstick, with cooking spray, then line the bottom with a parchment paper round. Wrap the outside of the pan with aluminum foil (preferably one sheet of heavy-duty foil).
2. If using, stir 1/2 cup raisins and 2 tablespoons rum together in a small bowl. Let soak while you make the base and meringue.
3. Beat 12 ounces room-temperature cream cheese and 6 room-temperature large egg yolks together in a stand mixer with the whisk attachment on low speed until smooth and combined, scraping down the bowl halfway through, about 3 minutes total.
4. Beat in 1/2 cup plus 2 tablespoons whole milk and 1/2 teaspoon lemon juice, scraping down the bowl halfway through, until smooth, about 1 minute total.
5. Sift 1/2 cup plus 1 tablespoon cake flour over the mixture. Gently fold it in with a flexible spatula until no dry flour remains. Transfer to a fine-mesh strainer set over a large bowl and strain to remove any lumps; make sure to scrape the underside of the strainer. Refrigerate while making the meringue.
6. Wash and dry the mixer bowl and whisk attachment. Beat 6 room-temperature large egg whites and 1 tablespoon cream of tartar together in the stand mixer with the whisk attachment on medium speed until foamy, about 1 minute.
7. With the mixer running, slowly stream in 3/4 cup plus 2 tablespoons granulated sugar and beat until glossy and barely soft peaks form (they should bend slightly when lifted), about 1 minute and 15 seconds.
8. Transfer about one-third of the meringue into the egg yolk base and gently whisk in by hand until just combined. Switching to a flexible spatula, fold in the remaining meringue in two additions just until combined; do not overmix.
9. If using raisins, drain and then sprinkle into an even layer in the springform pan. Transfer the batter to the pan and smooth out the top.
10. Place the springform pan in a roasting pan. Add enough hot water to the roasting pan to go about halfway up the sides of the springform pan, being careful not to get any into the springform.
11. Place the roasting pan in the oven. Immediately reduce the oven temperature to 300°F and bake undisturbed until evenly golden-brown on top and a tester inserted into the center comes out clean, about 1 hour.
12. Turn off the oven. Prop the door open with a wooden spoon and let the cheesecake remain in the oven for 10 minutes. Remove the springform pan from the water bath, remove the foil, and place the pan on a wire rack. Let cool completely to room temperature, about 2 1/2 hours.
13. Lightly cover (do not let the cover touch the surface of the cheesecake). Refrigerate until completely chilled, at least 4 hours or up to overnight. To serve, remove the sides of the pan. Dust with powdered sugar if desired before slicing and serving. For the cleanest-looking slices, use a knife dipped in hot water that’s wiped dry between each cut.