Ingredients

2 cups sifted superfine sugar (about 1 pound)
1 1/3 cups sifted cake flour (not self-rising)
1 1/2 cups egg whites at room temperature (10 to 12 eggs)
3/4 teaspoon kosher salt
1 1/2 teaspoons cream of tartar
1 teaspoon pure vanilla extract
1/2 cup coarsely grated semisweet chocolate

For the glaze:
1/2 pound semisweet chocolate chips
3/4 cup plus 1 tablespoon heavy cream

Instructions

Preheat the oven to

350 degrees F.

Combine 1/2 cup of the sugar with the flour and sift them together 4 times. Set aside.

Place the egg whites, salt, and cream of tartar in the bowl of an electric mixer fitted
with the whisk attachment and beat on high speed until the eggs form medium-firm peaks,
about 1 minute. With the mixer on medium speed, add the remaining 1 1/2 cups of sugar by
sprinkling it over the beaten egg whites. Beat on high speed for a few minutes until thick
and shiny. Add the vanilla and continue to whisk until very thick, about 1 more minute.
Scrape the beaten egg whites into a large bowl. Sift 1/4 of the flour mixture over the egg
whites and fold it very carefully into the batter with a rubber spatula. Continue adding
the flour in 3 equal additions, sifting and folding until it's all incorporated. Fold in
the grated chocolate.

Pour the batter into an ungreased 10-inch tube pan, smooth the top, and bake it for 35 to
45 minutes, until it springs back to the touch. Remove the cake from the oven and invert

the pan on a cooling rack. When cool, run a thin, flexible knife around the cake to remove
it from the pan.

For the chocolate glaze, place the chocolate chips and the heavy cream in a heat-proof
bowl over a pan of simmering water and stir until the chocolate melts. Pour the chocolate
over the top of the cooled cake to cover the top completely and allow it to drizzle down
the sides. If you have chocolate glaze left over, you can serve it on the side with the
cake.