1(13.5 ounce) jar natural Bordeaux maraschino cherries
2tablespoonscherry liqueur such as Kirschwasseroptional
Preheat oven to 275 degrees. Line a baking sheet with parchment paper.
Beat the egg whites on high speed until foamy. Gradually add the sugar and continue to beat until they form stiff, glossy peaks. Turn off the mixer; add the tapioca (or corn) starch, vinegar, and 2 teaspoons vanilla then beat in to the egg whites, scraping the sides of the bowl if necessary. Sift the cocoa powder into the egg whites and fold in with a rubber spatula until the mixture is no longer streaky. Dump the mixture onto the prepared baking sheet and using the back of a large spoon, push the mixture into a circle about 8 inches in diameter with a well in the center. Bake for 1 hour or until the outside is crispy, turn off the heat and let sit in the oven for another hour. Remove from oven and let cool completely.
While the meringue is cooling, drain the cherries, reserving the juice. Put the juice into a small saucepan with the cherry liqueur, if using, and bring to a boil. Continue to boil until the mixture is reduced by half. Let cool. Remove the stems from most of the cherries (leave a couple stems on for a nice presentation.)
Whip the cream with the remaining teaspoon of vanilla.
Place the meringue on a serving plate; fill the well in the center with the whipped cream, drizzle on the sauce, top with the cherries and sprinkle the top with grated chocolate. Serve immediately. The components can be made ahead and assembled just before serving.