- Butter for the pan
- 2 cups fresh whole-milk ricotta cheese (16 oz / 452g)
- 1 cup heavy cream (8.2 oz / 232g), chilled 4 large eggs (7 oz / 200g), separated
- 1 large egg yolk (0.6 oz / 16g)
- 1 tablespoon finely grated lemon zest
- 2 teaspoons vanilla extract
- ½ teaspoon plus a pinch of diamond crystal kosher salt
- 1 cup plus 1 tablespoon sugar (7.5 oz / 213g)
- 1 cup all-purpose flour (4.6 oz / 130g)
- 8 ounces small, thin-skinned tangerines (about 2 / 227g), halved and seeded, then very thinly crosswise
- 1 tablespoon fresh lemon juice (0.5 oz / 14g)
- ½ cup sugar (3.5 oz / 100g)
- Seeds scraped from ½ vanilla bean or 1 teaspoon vanilla extract
Preheat the oven and prepare the pan: Arrange an oven rack in the center position and preheat the oven to 375°f. Butter the bottom (not the sides) of a 9-inch springform pan and line it with a round of parchment paper. Butter just the parchment paper and set the pan aside.
Whip the ricotta and cream:
In a food processor, combine the ricotta and heavy cream and process until the mixture is very thick, whipped, and completely silky smooth, about 1 minute.
Add the remaining wet ingredients: Add the 5 egg yolks, the lemon zest, vanilla, 1⁄2 teaspoon of the salt, and 1 cup of the sugar (7 oz / 200g) to the ricotta mixture. Pulse the food processor, scraping down the bowl once, until all of the ingredients are well combined and the mixture is smooth and fluid.
Add the flour: Add the flour and pulse just to combine. Transfer the ricotta mixture to a large bowl and set aside.
Whip the egg whites: In a stand mixer fitted with the whisk attachment (or in a large bowl if using a hand mixer), beat the egg whites and the pinch of salt on medium-low just to break them up. Increase the speed to medium-high and beat until the whites form soft peaks. Gradually sprinkle in the remaining 1 tablespoon sugar and continue to beat on high until the whites are shiny, quadrupled in volume, and hold a firm peak off the end of the beater, about 2 minutes.
Fold in the egg whites:
Scrape the egg whites into the bowl with the ricotta mixture and use a large flexible spatula to gently fold the mixture until no streaks remain.
Fill the pan and bake: Scrape the batter into the prepared pan and smooth the top. Bake until the edges are deeply browned and the center is risen, cracked, and golden brown and a cake tester or toothpick inserted into the center comes out clean, 40 to 45 minutes (it will still wobble quite a bit when done). Transfer the pan to a cooling rack. The cake will fall and crater immediately, which is normal. Let the cake cool completely in the pan.
Make the marmalade: While the cake is cooling, place the sliced tangerines in a small saucepan and cover with cold water. Bring the mixture to a boil over medium-high heat, then drain the tangerines and rinse with cold water. Place back in the same saucepan along with the lemon juice, sugar, vanilla seeds, and 2 tablespoons water. Bring to a boil over medium heat, then reduce the heat to maintain a gentle simmer and continue to cook, stirring often and skimming off any white foam that accumulates on the surface, until the liquid has thickened to the consistency of maple syrup and the tangerine slices are softened and mostly translucent, 15 to 20 minutes. Set aside and let the marmalade cool completely.
Serve: Use a small offset spatula or paring knife to cut around the sides of the pan to release the cake and remove the metal ring. Spread the cooled marmalade over the top of the ricotta cake (or serve alongside).
Do ahead: The cake, covered and refrigerated, will keep up to 4 days but is best served on the first or second day. Let it come to room temperature and top with
The marmalade before serving:
The marmalade, covered and refrigerated, will keep up to 2 weeks.