I’ve long loved blood oranges for their crimson beauty and unique pomegranate-meets-citrus flavor. To me, their potential as a dessert ingredient is simply undeniable. So, at the height of citrus season, it was no surprise that I headed to the market on a mission to transform them into a delectable new treat.
I decided on a light, vibrant cake made with plenty of blood orange juice and zest, a splash of vanilla and the pleasant crackle of poppy seeds for a delicately nutty balance. A bit of lime would add a complementary zing, while a dazzling but easy glaze would flaunt the oranges’ tang and hue.
Speaking of that hue, a funny thing can happen when making this cake. If the blood oranges are deeply red and ripe, their reaction with the baking soda results in a blue crumb. The flavor is unaffected — it’s as citrusy and fresh as ever — and the cake’s texture remains moist and airy. The blueness merely adds a bit of whimsy while it contrasts beautifully with the pink icing, and the indigo poppy seeds enhance the unusual color. And I love the inherent reminder that baking is full of unexpected magic.
Aside from the labor of zesting and juicing, this is a rather simple recipe that goes fast. The glaze process may at first appear fussy, but it’s done in just a few painless minutes. As with this recipe, heating the liquid helps trigger the thickening power of the cornstarch in the powdered sugar, which not only makes the glaze set quickly but also prevents it from soaking into the cake. Flavor-wise, the glaze offers a burst of sweet citrus that enrobes a tender, tangy cake balanced with warm vanilla and toasty seeds.
Blood Orange Poppy Seed Cake
2 small limes 6-8 medium blood oranges (about 2 1/2 to 3 pounds) 1 large egg 1/2 cup granulated sugar 1/3 cup vegetable oil, such as sunflower or canola 2 teaspoons pure vanilla extract 1 1/2 cups all-purpose flour 1 1/2 teaspoons baking powder 1 1/4 teaspoons baking soda 1/4 teaspoon salt, plus a dash for the glaze 2 tablespoons poppy seeds 1 3/4 cups powdered sugar, very well-packed*
Preheat oven to 350ºF. Lightly grease the inside of an 8″ round cake pan; line the inner bottom with a circle of parchment paper. Set aside.
Wash and dry the citrus fruit. Using a Microplane or similarly sized zester, finely grate the outer peel of one lime and 4–5 oranges (you want about 15 grams total zest). Set aside.
Halve and juice both limes, followed by the blood oranges. Remove any seeds; some bits of pulp are fine. Stop when you have 1 1/2 cups total strained citrus juice. (You may end up with extra oranges depending on their juiciness; use as you wish.)
In a large bowl, beat the egg and granulated sugar until combined. Beat in the oil and vanilla until smooth. Over the bowl, sift the flour, baking powder, baking soda, and 1/4 teaspoon salt. Begin to stir, gradually adding 1 1/4 cups of the citrus juice (reserve remaining 1/4 cup juice for the glaze). Mix just until batter is an even consistency and all ingredients are incorporated.
Gently fold in the poppy seeds and citrus zest until evenly dispersed. Pour batter into prepared cake pan. Bake on center rack in preheated oven, 35-40 minutes or until cake is golden brown and slightly domed, and a wooden toothpick inserted in the center tests clean of wet batter. Don’t worry if the cake has cracked.
Let cake cool to room temperature in pan; this can take more than an hour. If not glazing cake right away, cover cooled cake tightly, and store at room temperature. When ready to glaze, invert and release cake, remove parchment, and place cake right-side-up on a rack over a platter or wax paper.
Measure powdered sugar (see note), then sift into a bowl; set nearby. Place three tablespoons of the remaining citrus juice in a small saucepan with a dash of salt. Over medium heat, bring juice just to a steady simmer. Turn off heat completely, and — working quickly — add the powdered sugar to the pan. Whisk vigorously until smooth. Immediately pour glaze directly over the cake, letting it drip down the sides. If desired, use any remaining glaze to create a zig-zag design. Glaze should dry quickly at room temperature, uncovered.
Keep the glazed cake in a cool, dry place (unrefrigerated) until ready to serve, uncovered or loosely covered. This will allow the glaze to stay set. Cover any leftover slices and keep at room temperature or chilled, eating within two days.
*Make sure your powdered sugar contains cornstarch (most standard brands do). When measuring, the 1.75 cup should be very well packed, weighing 7.5 ounces or 215 grams. If you don’t have a scale and/or the glaze seems too thin, feel free to whisk in more powdered sugar until desired consistency is reached. Color of glaze will be affected by the hue of the juice.