1 package (2-layer size) chocolate cake mix plus ingredients to prepare mix
2 cans (20 ounces each) tart pitted cherries, undrained
1 cup granulated sugar
1/4 cup cornstarch
1‑1/2 teaspoons vanilla
Preheat oven to 350°F. Grease and flour two 9-inch round cake pans; set aside.
Prepare cake mix according to package directions. Divide batter between prepared pans.
Bake 30 to 35 minutes or until toothpicks inserted into centers come out clean. Cool in pans on wire racks 10 minutes. Remove from pans; cool completely on racks.
Meanwhile, drain cherries, reserving 1/2 cup juice. Combine reserved juice, cherries, sugar and cornstarch in 2-quart saucepan. Cook over low heat until thickened, stirring constantly. Stir in vanilla. Prepare Frosting.
With long serrated knife, split each cooled cake layer horizontally in half. Crumble one split layer; set aside.
Reserve 1-1/2 cups Frosting for decorating cake. Place one cake layer on cake plate. Spread with 1 cup Frosting; top with 3/4 cup cherry topping. Top with second cake layer; repeat layers of Frosting and cherry topping. Top with third cake layer.
Frost side of cake with remaining Frosting. Pat reserved crumbs onto frosting on side of cake. Spoon reserved frosting into pastry bag fitted with star decorator tip. Pipe around top and bottom edges of cake. Spoon remaining Cherry Topping onto top of cake.
Combine 3 cups cold whipping cream and 1/3 cup powdered sugar in chilled deep medium bowl. Beat at high speed of electric mixer until stiff peaks form.