Prepare cake according to package directions using two 9-inch round baking pans. Remove from oven and allow to cool completely. Drain cherries, reserving ? cup liquid. Cut cherries in half; set aside.
In small saucepan, over medium-low heat, combine chocolate chips and milk, cook until melted and smooth, whisking constantly. Remove from heat and cool slightly.
In large mixing bowl, combine whipped topping, cream cheese and sugar; mix with an electric mixer until well combined and smooth.
Place one cake round on serving platter. Brush with half the reserved cherry juice. Spread half of chocolate over cake and 1/3 whipped topping mixture; top with cherries. Repeat layer with remaining cake, cherry liquid and chocolate. Spread remaining whipped topping over top and sides of cake. Refrigerate, covered, until ready to serve.