Ingredients
8 egg yolks
1 cup (200 g) white sugar
1 tbsp orange zest
0.75 cup (90 g) matzo cake meal
0.25 cup (30 g) potato starch
8 egg whites
0.5 cup (100 g) white sugar
1.5 tbsp fresh orange juice
Directions
Step 1
Preheat the oven to 325°F (165°C). Grease and line the bottom of a 10-inch tube pan with parchment paper.
Step 2
In a medium bowl, whisk the egg yolks until light in color. Gradually add 1 cup of sugar and the orange zest, whisking until thick and pale, about 7 minutes.
Step 3
Sift the matzo cake meal and potato starch together; set aside.
Step 4
In a large glass or metal mixing bowl, beat the egg whites until foamy. Gradually add the remaining 1/2 cup of sugar, continuing to beat until stiff peaks form. Fold the matzo mixture into the yolk mixture alternately with the orange juice. Fold 1/3 of the whites into the batter, then quickly fold in the remaining whites until no streaks remain. Spread the batter evenly into the prepared pan.
Step 5
Bake the cake for about 1 hour, checking after 45 minutes, until a toothpick inserted into the center comes out clean. Invert the pan onto a wire rack to cool. Run a knife around the sides of the cake before removing from the pan.