- 2 cups sugar
- 1 1/3 cups sifted cake flour (not self-rising)
- 1 1/2 cups egg whites (from 10 to 12 large eggs), at room temperature
- 3/4 teaspoon kosher salt
- 1 1/2 teaspoons cream of tartar
- 3/4 teaspoon pure vanilla extract
- 1 1/2 teaspoons grated orange zest (from 1 large orange), plus 2 to 3 tablespoons freshly squeezed orange juice
- 1 cup confectioners sugar
- 1/4 teaspoon cinnamon
Preheat the oven to 350F.
Put 1/2 cup sugar and the flour in a bowl, and sift together 4 times, or pulse together in a food processor fitted with the steel blade. Set aside.
Put the egg whites, salt and cream of tartar in the bowl of a stand mixer fitted with a whisk attachment and beat on high speed until there are medium-firm peaks, about 1 minute. With the mixer on medium speed, add the remaining 1 1/2 cups of sugar by sprinkling it over the beaten egg whites in a constant stream. Beat for a few minutes until thick and shiny. Beat in the vanilla and orange zest and continue to whisk until very thick, about 1 more minute. Sift about 1/4 of the flour mixture over the egg whites and fold it into the batter with a rubber spatula. Continue adding the flour by fourths, by sifting and folding until all the flour is incorporated.
Pour the batter into an ungreased 10-inch tube pan, smooth the top, and bake until it springs back to the touch, and a toothpick inserted into the center comes out clean, about 40 to 45 minutes. Remove the cake from the oven and invert the pan on a cooling rack until cool, 1 to 1 1/2 hours.
While the cake is cooling, make the glaze by putting the confectioners sugar and orange juice in a bowl and stirring together until the sugar is dissolved and a thin, syrupy consistency is attained. Stir in the cinnamon.
Once cooled, unmold the cake from the pan and drizzle the glaze over the top, using the tines of a fork.