In a bowl, combine cherries and kirsch. Let stand at least 30 minutes, stirring occasionally.
Oil a metal 8-inch-wide round cake pan. Line pan bottom with waxed paper cut to fit; oil paper. Dust pan with cocoa, shaking out excess.
In a bowl, mix 2/3 cup cocoa, flour, soda, and salt.
In another bowl with a mixer, beat to blend sugar, 1/4 cup salad oil, egg whites, vanilla, and 1 cup water. Add flour mixture; stir to mix, then beat until batter is smooth. Scrape batter into prepared pan.
Bake in a 350° oven until cake begins to pull from pan side and springs back when lightly pressed in center, 35 to 40 minutes.
Let cool in pan on a rack for 10 minutes. Run a thin knife between cake and pan rim, invert cake onto a rack, lift off pan, and gently pull off and discard waxed paper. Let cool about 1 hour. When cake is cool, use a long serrated knife to cut the cake horizontally into 3 equal layers.
Meanwhile, follow directions for whipped frosting, using 2 large egg whites, 1 cup sugar, 1/4 cup water, 1/4 teaspoon cream of tartar, and 1 teaspoon vanilla.
Drain cherries, pouring kirsch into a small pitcher.
To assemble cake, place bottom layer on a flat plate, cut side up. Spread cut side with about 1/4 the frosting; dot with 1/2 the cherries. Set center cake layer on frosting; spread with about 1/4 the frosting; dot with remaining cherries. Lay top of cake, cut side down, onto cherries. With a small spatula, swirl remaining frosting over cake. Cut cake into wedges; drizzle each portion with reserved kirsch.
Notes: If desired, mound up to 2 tablespoons semisweet chocolate curls on top of the frosted cake.