Preheat oven to 325°F (170°C).

In a medium bowl, sift together flour, 1 cup (200 grams) sugar, and cocoa.

In the bowl of a stand mixer fitted with the whisk attachment, beat egg whites at medium-high speed until foamy, about 1 minute. Slowly add remaining 1 cup (200 grams) sugar. Increase mixer speed to high; immediately add cream of tartar and salt. Add vanilla. Beat until medium- soft peaks form, 2 to 3 minutes. Using a large balloon whisk, gently fold in flour mixture in four additions until just combined. Gently spread batter into an ungreased 10-inch tube pan. Run a knife through batter to remove any large air pockets. Smooth top with a small offset spatula.

Bake until cake is firm to the touch and an instant-read thermometer inserted near center registers 205°F (96°C), 45 to 50 minutes. Immediately invert pan (onto a bottle if needed), and let cool completely.

Using an offset spatula, loosen cake from sides, center, and bottom of pan. Place cake on a cake plate. Serve with Vanilla Chantilly Cream and Roasted Cherries. Store in an airtight container for up to 3 days.