- 1 cup cake flour, sifted
- 1 1/2 cups sugar, divided
- 12 large egg whites, at room temperature
- 1 tablespoon orange flower water
- 1/2 teaspoon vanilla extract
- 1/2 teaspoon cream of tartar
- 1/4 teaspoon salt
- 1 tablespoon grated orange zest
- 1/4 cup fresh orange juice
- 1/4 cup water
- 1/2 cup unsweetened cocoa powder
- Orange slices (optional)
- Preheat the oven to 350 degrees F (180 degrees C).
- To Make the Cake: In a small bowl, whisk together the cake flour and 1/2 cup (125 ml) of the sugar; set aside.
- In a large bowl, with an electric mixer at medium speed, beat the egg whites, orange-flower water, vanilla, cream of tartar, and salt until soft peaks form. With the mixer at medium-high speed, slowly add the remaining 1 cup (250 mL) sugar, 1 tablespoon (15 mL) at a time, continuing to beat until the whites are stiff but not dry.
- Gently fold the reserved flour-sugar mixture into the egg whites, then fold in the orange zest.
- Pour the batter into a 10-inch (4-L) tube pan and run a knife through the batter to remove any air bubbles.
- Bake for 30 minutes, or until the top springs back when lightly touched and a cake tester or toothpick inserted in the center comes out clean.
- Remove the cake from the oven and invert on a wire rack. Let cool in this position until the pan is no longer hot. To remove the cake, run a sharp, thin-bladed knife around the sides and inner tube of the pan. Lift the cake out of the pan, then remove the bottom of the pan. Place the cake on a serving plate.
- To Make the Sauce: In small saucepan, combine the sugar, orange juice, and water, and bring to a boil over medium-high heat.
- Reduce the heat to low and whisk in the cocoa powder until smooth.
- If desired, top the whole cake with orange slices before cutting. Serve with the Chocolate Sauce.