2 cans (20-oz) cans tart pitted cherries, undrained
1 cup granulated sugar
1/4 cup cornstarch
1 1/2 tsp vanilla extract
2 (9-inch) baked chocolate cake layers, cooled
3 cups cold whipping cream
1/3 cup powdered sugar
Drain cherries, reserving 1/2 cup of the juice. Combine reserved cherry juice, cherries, granulated sugar, and cornstarch in a saucepan. Turn heat to a low setting and cook, stirring, until thickened. Add the vanilla extract and stir to blend.
Split each of the cake layers in half horizontally. Crumble one of the half layers and set aside. Place one of the cake layers on the serving plate. Set other two aside.
Beat the cold whipping cream and the powdered sugar together in a large mixing bowl using an electric mixer set on high speed. Beat until stiff peaks form. Reserve 1 1/2 cups whipped cream for piping, if desired. Spread 1 cup of the whipped cream on the layer on the serving plate. Top with 3/4 cup cherry topping. Top with the second layer, 1 cup whipped cream, and the 3/4 cup cherry topping; top with the third layer. Frost sides of cake with the remaining whipped cream. Pat the reserved cake crumbs gently on the sides of the cake. Spoon the remaining whipped cream into a pastry bag with a star tip; pipe around the edges of the cake. Spoon the remaining cherry topping over the top of the cake.