Preheat oven to 350°F. For the Cake, microwave chocolate and butter in medium microwavable bowl on HIGH 2 minutes or until butter is melted. Stir until chocolate is completely melted. Cool 5 minutes.
Beat cake mix, milk, eggs, raspberry flavor and cooled chocolate mixture in large bowl with electric mixer on low speed just until moistened, scraping side of bowl frequently. Beat on medium speed 2 minutes or until well blended. Pour evenly into 2 greased and floured (9-inch) round cake pans.
Bake 25 to 28 minutes or until toothpick inserted in centers comes out clean. Cool cakes in pans 10 minutes; remove from pans. Cool completely on wire racks.
For the Frosting, melt chocolate as directed on package. Cool 5 minutes. Beat cream cheese and butter in large bowl with electric mixer on medium speed until well blended. Add cooled melted chocolate and raspberry flavor; mix well. Gradually beat in confectioners’ sugar until light and fluffy. Stir food color into 2/3 cup of the frosting until well blended.
Place 1 cake layer on serving plate. Spread with the tinted frosting. Top with remaining cake layer. Frost top and side of cake with remaining frosting. Top with raspberries just before serving. Store cake in the refrigerator.