I made this cake for Easter, with homemade raspberry/blackberry jam, which I made many jars of in celebration of plumbers who unplugged our deep freeze and didn't plug it back in, causing the defrosting of our frozen berries. I found my sponge cake a bit dry, but that might have been because my Easter brunch got postponed a day due to snowstorm. It might also have been because I got distracted and beat the hell out of the egg whites.
The sponge cake recipe is adapted from Rebecca Reilly's indispensable Gluten-Free Baking.
Dad said his mother called this kind of cake "Washington Pie."
3/4 cup sweet rice flour
1/2 cup potato starch flour
5 eggs, brought to room temperature and separated
1 1/4 cups sugar
2 tsp vanilla
2 tsp grated lemon peel
2 tbsp lemon juice, plus 1/2 tsp
1/4 tsp salt
2 cups heavy cream
1/4 cup GF icing sugar
2/3 cup raspberry jam
1/2 cup chopped unsalted pistachios
Preheat oven to 325F. Line two 9" round cake pans with parchment paper and set aside.
In a small bowl, whisk flour and starch. Set aside.
In a large bowl, beat egg yolks and sugar until pale yellow and ribbons form. Stir in vanilla, lemon peel, and 2 tbsp lemon juice (reserving the 1/2 tsp for later).
In a medium glass or copper bowl, beat egg whites with lemon juice and salt until soft peaks form.
Fold 1/4 of the egg white mixture into the egg yolk mixture, to loosen. Pour remaining egg whites over top and sprinkle gently with flour mixture. Fold until well-blended. Pour into prepared pans. Bake for 20 to 25 minutes or until surface springs back from a light touch (though this test is tricky because rice flour is crustier than it is springy). Invert pans on a cake rack until fully cooled.
When the cake is fully cool, slice cake layers in half horizontally with a serrated knife, to make four layers in all. Whip cream with icing sugar.
Place the bottom cake layer on a cake plate; spread with 1/3 of the jam and top with 1/4 of the whipped cream. Repeat with next two layers. Top with remaining layer and spread remaining cream on top and sides. Decorate top with chopped pistachios.
