- For cake:
- 1/2 cup matzo cake meal
- 1/2 cup potato starch
- 1/4 teaspoon salt
- 2/3 cup medium-dry Concord-grape wine
- 3 tablespoons fresh lemon juice
- 6 large eggs, separated, at room temperature for 30 minutes
- 1 1/2 teaspoons finely grated fresh lemon zest
- 1 1/4 cups granulated sugar
- For strawberries:
- 2 pounds strawberries, trimmed and quartered
- 1/4 cup medium-dry Concord-grape wine
- 4 teaspoons granulated sugar
- Make cake: Put oven rack in middle position and preheat oven to 350 degrees F.
- Whisk together matzo cake meal, potato starch, and salt in a bowl. Stir together wine and lemon juice in another bowl or a glass measure.
- Beat yolks in a large bowl with an electric mixer at medium-high speed until smooth, then add zest. Add 1 cup sugar gradually, beating, and beat until mixture is very thick and pale, 2 to 3 minutes.
- With mixer at low speed, add half of matzo cake meal mixture to yolks, then all of wine mixture. Add remaining matzo meal mixture, mixing until just combined.
- Beat whites with a pinch of salt in another bowl with cleaned beaters at medium speed until they hold soft peaks. Add remaining 1/4 cup sugar a little at a time, beating, and beat until whites just hold stiff peaks. Fold one fourth of whites into yolk mixture to lighten, then fold in remaining whites gently but thoroughly.
- Pour batter into ungreased tube pan and rap pan firmly three times on work surface to eliminate any large air bubbles.
- Bake sponge cake until top is golden and springs back when it is pressed gently, 35 to 40 minutes. Immediately turn pan upside down on a rack and cool completely, about 1 hour. Run a knife around inner and outer edges of cake to loosen, then remove from pan.
- Macerate strawberries: While cake cools, gently stir together strawberries, wine, and sugar until sugar is dissolved, then let stand at least 30 minutes.
- Dust cake with Passover confectioners sugar and serve with strawberries.