Serves: Makes 10 to 12 servings
- 1¾ cups (6 ounces) sifted cake flour
- 1 cup minus 2 tablespoons (6 ounces), plus ¼ cup (1¾ ounces) granulated sugar
- 1½ teaspoons baking powder
- 188; teaspoon salt
- 1½ cup (3¼ ounces) poppy seeds (optional)
- ¼ cup plus 2 tablespoons (3 ounces) flavorless vegetable oil, such as safflower or canola
- 6 large eggs, separated
- Finely grated zest of 2 large tangerines
- ½ cup (4 ounces) strained freshly squeezed tangerine juice
- 1½ teaspoons pure vanilla extract
- ¼ teaspoon pure tangerine oil
- ¾ teaspoon cream of tartar
- 2 cups (6¾ ounces) confectioners' sugar
- 3 tablespoons strained freshly squeezed tangerine juice
- ⅛ teaspoon pure tangerine oil
- Fresh, organic citrus blossoms, Sugared
- Flowers, or candied tangerine zest, for garnish
- Preheat the oven to 325°F and position an oven rack in the lower third.
- Make the cake: With the fine-mesh strainer, sift the cake flour, the 1 cup minus 2 tablespoons granulated sugar, the baking powder, and salt into the large bowl. Add the poppy seeds and whisk to blend. Make a well in the center and pour in the oil, egg yolks, tangerine zest and juice, vanilla extract, and tangerine oil. Whisk vigorously until the mixture is very smooth. Set aside.
- Make sure your whisk attachment (or beaters) and your mixing bowl are scrupulously clean. In the bowl of the stand mixer, whip the egg whites on medium just until frothy. You can also use a hand mixer and a medium bowl. Add the cream of tartar and whip on medium-high until soft peaks form. With the mixer on medium, slowly add the remaining ¼ cup of granulated sugar and whip until the whites hold very firm peaks. (This cake requires stiff egg whites for its height and open texture, so don't be afraid to beat a few seconds longer than you normally would for firm peaks.) To check for firm peaks, with a spoon scoop bowl when the spoon was lifted should hold their shape.
- Use the spatula to gently stir a mound of beaten whites into the bowl of batter. This step slightly lightens and loosens the mixture, making it easier to fold in the remaining whites without deflating them. Scrape the remaining egg whites into the bowl and gently but thoroughly fold them into the batter until no streaks of egg whites remain.
- Scrape the batter into the pan and smooth the top. Bake for 50 to 60 minutes, until the cake has risen, the top is lightly golden and feels firm to the touch, and a skewer inserted into the center comes out clean. Immediately invert the pan onto its feet or over the wine or soda bottle. Allow to cool completely, at least 2 hours.
- Invert the cake so it is right side up. Run the thin, flexible knife or spatula around the edges to loosen it from the pan. As you do this, gently press the knife into the side of the pan to avoid gouging the cake. Push the removable bottom upward to free the cake from the side. Run the same knife around the inside tube and along the bottom of the cake, if necessary, to finish loosening it. Place a plate on top of the cake and invert, removing the cake from the pan. Depending on the look you want, either leave the cake upside down on the plate or invert it again to set it right side up.
- Make the icing: With the fine-mesh strainer, sift the confectioners' sugar into the medium bowl. Whisk in the tangerine juice and tangerine oil until the mixture is very smooth. Spoon over the top of the cake, directing some of the icing right onto the edges so that it cascades down the sides. Immediately garnish the top of the cake with the citrus blossoms, sugared flower petals, or candied zest. As the glaze hardens, it will anchor the garnishes to the cake. To serve, slice with the serrated knife using a gentle sawing motion.
Storing: The cake will keep well at room temperature, covered with plastic wrap or under a cake dome, for several days. Once cut, press a piece of plastic wrap firmly against the cut surfaces to help keep it fresh