6 large eggs separated plus 1 (30 grams) additional egg white
2 1/4 cups (225 grams) sifted cake flour
1 1/2 cups (300 grams) superfine white (castor) sugar
1 tablespoon baking powder
1/2 teaspoon salt
1/2 cup (120 ml) vegetable oil or canola oil
3/4 cup (180 ml) freshly squeezed orange juice (2 – 3 large Navel Oranges)
2 tablespoons (10 grams) orange zest
1 teaspoon pure vanilla extract
3/4 teaspoon cream of tartar
Separate the eggs and place the whites in one bowl and the yolks in another. Cover with plastic wrap and bring them to room temperature (about 30 minutes).
Preheat the oven to 325 degrees F (170 degrees C) and have ready a 10 inch (25 cm) two piece tube pan (ungreased).
In the bowl of your electric mixer, fitted with the paddle attachment, place the flour, sugar (minus 3 tablespoons (42 grams)), baking powder, and salt. Beat until combined. Make a well in the centre of the flour mixture and add the egg yolks, oil, orange juice, orange zest, and vanilla extract. Beat for about one minute or until smooth.
In a separate bowl, beat the egg whites until foamy with the whisk attachment. Add the cream of tartar and continue to beat until soft peaks form. Gradually beat in the remaining 3 tablespoons (42 grams) of sugar and beat until stiff peaks form. With a large rubber spatula or wire whisk, gently fold the egg whites into the batter just until blended (be careful not to deflate the batter).
Pour the batter into the ungreased 8” pan and bake for about 40 to 45 minutes, or until a wooden skewer inserted into the center of the cake comes out clean. (When lightly pressed the cake will spring back). Immediately upon removing the cake from the oven invert the pan and place on a bottle or flat surface so it is suspended over the counter. Let the cake cool completely before removing from pan (about 1 1/2 – 2 hours).
To remove the cake from the pan, run a long metal spatula around the inside of the tube pan and center core. Invert onto a greased wire rack.
Can store in an airtight container for a few days at room temperature or for about a week in the refrigerator. This cake can also be frozen for a couple of months.
Note: To make superfine sugar, process 1 1/2 cups (300 grams) of granulated white sugar in your food processor for about 30 seconds or until finely ground. Superfine sugar is used as it dissolves easier in the batter.
Orange Zest – The orange outer rind of the orange that contains the fruit’s flavor and perfume.
Cream of tartar is tartaric acid and is a fine white crystalline acid salt that is a by-product of the wine-making industry. It is used in the whipping of egg whites to stabilize them and allow them to reach maximum volume.