With their blushed skin and crimson flesh, blood oranges are the perfect ingredient for Valentine's Day or any winter occasion that could use a shot of color. Baked in a skillet, here's a blood orange dessert that's more rustic than fussy, and delicious with a hot cup of tea or coffee. The oranges caramelize and soften in the oven yet retain a trace of bitterness in the rinds, which plays nicely against the moist and syrupy sweet almond cake. The cake itself is a riff on the classic — and naturally gluten-free — Galician Tarta de Santiago as it appears in Claudia Roden's "The Food of Spain."
For the reddest color, look to use Moro or Sanguinello blood oranges. However, the cake would be delicious with Tarocco blood oranges or indeed any variety of orange.
Blood Orange and Almond Upside-Down Cake
2 medium blood oranges
3 tablespoons unsalted butter
2/3 cup brown sugar
5 large eggs, separated
1 cup superfine sugar
Finely grated zest of 1 lemon
Finely grated zest of 1 orange
1 teaspoon vanilla extract
1/2 teaspoon ground cinnamon
8 ounces blanched almonds, finely ground in a food processor
Crème fraîche (optional)
Preheat the oven to 350°F with a rack in the center.
Using a sharp knife, trim and discard the top and bottom ends of the blood oranges and then cut the oranges into 1/8-inch-thick rounds. Remove and discard any seeds. Set aside.
Place the butter and brown sugar in a 10-inch oven-proof skillet over medium heat. Cook, stirring, until the butter and sugar are melted and evenly spread across the bottom of the skillet. Remove from heat. Arrange the orange slices on top of the brown sugar mixture, starting in the center and slightly overlapping to create concentric circles. Set aside.
Using an electric mixer, beat the egg yolks and sugar until pale and creamy. Beat in the lemon zest, orange zest, vanilla extract, and cinnamon. Add the ground almonds and mix until well combined.
Using clean dry beaters, beat the egg whites in another bowl until stiff peaks form. Add one-quarter of the egg whites to the almond mixture and stir to combine. Fold in the remaining egg whites. The mixture will be very thick and stiff, but work gently and patiently so as not to deflate the egg whites too much.
Pour the batter into the skillet without disturbing the oranges. Bake until the cake is set and a toothpick inserted in the center comes out clean, about 45 minutes.
Cool the cake in the skillet for 15 minutes. Run a knife along the edge of the cake to loosen it and invert it onto a plate. Rearrange any orange slices that may have stuck to the skillet. Cool cake completely at room temperature.
Serve with crème fraîche, if desired.