Special Equipment: 9-inch (23-cm) spring-form pan
For the glazed citrus (if not using Preserved Kumquats)
- small navel oranges, preferably organic
- 1/4 teaspoon kosher salt
For the clementine cake
Make the glazed citrus
Finely grate the zest of 2 of the citrus fruits and reserve the zest for the cake batter. Cut the citrus fruit in half, juice it, and strain the juice; you should have 1/3 cup juice. (There’s a chance you may need a second citrus to yield sufficient juice.) Slice the remaining citrus fruits into very thin rounds—not paper thin, mind you, but no more than 1/4 inch (6 mm) thick. Remove and discard any seeds.
Combine the citrus juice, lemon juice, sugar, salt, and orange slices in a medium nonreactive saucepan over low heat and bring to a slow simmer. Cook for 6 to 7 minutes, until the peels are tender and the centers of the orange slices are starting to become tender and translucent but are not falling apart. If the peels aren’t yet tender enough to cut with a fork, keep simmering until they are.
Using a slotted spoon, carefully transfer the orange slices to a coated wire rack. Continue to simmer the syrup until it has reduced to 1/2 cup. Remove from the heat.
Make the cake
Preheat the oven to 375°F (190°C). Line a 9-inch springform cake pan with parchment and arrange the glazed oranges on the batter in a single layer, fill any large gaps by cutting citrus pieces to fit. If using the preserves kumquats do your best to strain the fruit from the liquid. Otherwise, reserve the liquid for later use.
Combine the butter and sugar in the bowl of a stand mixer fitted with the paddle attachment and beat on medium speed until fluffy (about 3 mins). With the mixer still running, add one egg and mix until fully incorporated before adding the second egg. When the second egg is fully incorporated, sprinkle the grated orange zest reserved from the glaze recipe over the batter and mix until combined.
In a bowl, sift together the semolina flour (or almond flour), all-purpose flour, baking powder, and salt. Gently mix the flour mixture into the batter, a little at a time, and mix just until no white streaks of flour remain. Pour the batter into the prepared cake pan and smooth the surface.
Bake the cake for 15 minutes. Reduce the oven temperature to 350°F (177°C) and bake the cake for 35 to 40 minutes more for a total of 50 to 55 minutes, until the cake is an even golden brown and a toothpick inserted in the center comes out clean.
Using a wooden skewer, poke a handful holes of the cake. Brush the remaining glaze over the cakes using a pastry brush. Let the cake cool to warm and then flip upside down onto a cooling rack removing parchment. Cool room temperature on wire rack. Serve with fresh whipped cream or coconut cream.