This is a cake that I resurrected this year for Passover in Swaziland. I was able to attend two Seder dinners, and I made this for one of them because there was not much else I could make here in terms of desserts. This one, though, is simplicity at its best: few ingredients, few steps, and the result is an incredibly light, fluffy, and wonderful lemony dessert. Usually when my mother makes this, we just have it plain and serve it with strawberries, but I tried it this time with a layer of jam in the middle and it was fantastic! Everyone seemed to enjoy the taste! And if you are like me and don't have an electric mixer, you'll end up building your upper arm strength when you beat the egg whites into stiff peaks. Totally worth it, no question.
Lemon Sponge Cake with Jam Filling
1 1/2 cups sugar, sifted
2 tbsp. lemon juice
3/4 cup potato starch, sifted
dash of salt
Jam of your choice (strawberry and raspberry would work especially well)
Separate six of the eggs. Beat the six yolks and the one whole egg until frothy. Gradually add sifted sugar and lemon juice, beating constantly and thoroughly. Then gradually add sifted potato starch, stirring constantly to ensure thorough blending. Beat the egg whites with the salt until stiff but not dry. Fold gently but thoroughly into egg-yolk mixture. Place in ungreased 10-inch tube pan. Bake in a moderate oven (350 F) about 55 minutes or until cake springs back when touched gently with fingers. Invert pan and cool thoroughly before removing cake.
I do not actually have a tube pan in Swaziland, so I used a very deep 8" x 8" nonstick cake pan, and it works just fine as long as you still invert it until it is cooled.
Once cake has been removed, cut it in half carefully using a long knife. Set the top half aside on a piece of wax paper. Spread the jam of your choice generously over the bottom half and replace the top half of the cake again.
If you want to have a lemon glaze, mix together powdered sugar with lemon juice and potato or arrowroot starch until you get a good consistency.
1/2 c. powdered sugar (make sure there is no cornstarch in this if you want this to be kosher!)
1 tsp. potato or arrowroot starch, and more if needed
3 tsp. lemon juice
water to desired consistency
Drizzle over the cake and let harden before serving.