Angel Food Cake

from Martha Stewart's Cooking School book (thanks Chris and Jeni!)

1 1/4 cup sifted cake flour (not self-rising)

1 1/2 cups granulated sugar

12 large egg whites, room temperature

1/2 teaspoon salt

1 teaspoon cream of tartar

1 teaspoon vanilla extract

Heat oven and sift flour.  Heat oven to 325 F, with rack in lower third of oven.  Use a fine sieve to sift together flour and 3/4 cup granulated sugar over a sheet of parchment paper or a bowl.  Repeat sifting four times.

Make meringue.  Beat egg whites in a large, wide bowl with an electric mixer on low speed until foamy; add salt, cream of tartar, and vanilla.  Beat on medium speed until soft peaks form, about 3 minutes.  With mixer running, add remaining 3/4 cup sugar a little at a time, beating no more than 1 minute after each.  Raise speed to medium-high and beat until stiff glossy peaks form (when beater is lifted, only the tip of the peak should fall over slightly).

Fold flour into meringue.  Sift flour mixture over meringue in six parts, gently folding in each addition with a flexible spatula.  Be careful not to overmix or the egg whites will deflate.

Bake and cool.  Scrape batter into a 10-inch angel-food pan (or tube pan).  Run a knife through the batter to release any large air bubbles, and smooth with an offset spatula.  Bake until cake is golden brown and springy to the touch, 30 to 45 minutes.  Invert pan onto its legs (if using an angel-food pan) or a wire rack and let cool about 1 1/2 hours.  Carefully run a paring knife around side of cake to loosen, then turn out onto the rack.

Serve.  Place the cake on a serving platter and surround with berries; dust with confectioners' sugar.  Slice cake with a comb cutter or serrated knife; serve slices with berries and whipped cream.  Cake will keep up to 2 days at room temperature in an airtight container or wrapped well in plastic.