STEP ONEFor Cheesecake: HEAT oven to 300°F. Line bottom of 9-inch springform pan with parchment paper. Beat cream cheese in medium bowl with electric mixer on medium speed until creamy. Remove 1/3 cup sweetened condensed milk and chill for later use. Blend remaining sweetened condensed milk, chocolate and vanilla into cream cheese mixture. Add eggs, beating just until blended. Pour into prepared pan. Place pan on baking sheet. Bake 45 minutes or until set in center. Cool on wire rack 15 minutes. Run knife around edge of pan to loosen. Cool completely. Chill several hours or overnight.
STEP TWOFor Carrot Cake: HEAT oven to 350°F. Line 2 (9-inch) round baking pans with parchment or wax paper. Coat with no-stick cooking spray. Beat sugar, oil and eggs in large bowl with electric mixer on medium speed 2 minutes. Stir flour, salt, baking soda and cinnamon in small bowl until blended. Blend into egg mixture. Beat on medium speed 1 minute. Stir in carrots and raisins until blended. Spread evenly in prepared pans. Bake 45 to 50 minutes or until toothpick inserted into center comes out clean. Cool 15 minutes. Remove from pans to wire rack. Remove parchment paper. Cool completely.
STEP THREEFor Frosting: BEAT cream cheese in medium bowl with electric mixer on medium speed until smooth. Add 1/3 cup reserved sweetened condensed milk and frosting. Beat until smooth.
STEP FOURPLACE 1 cake layer on cake plate, rounded side down. Spread top with 2/3 cup frosting. Remove cheesecake from pan; discard parchment paper. Place on top of carrot cake layer. Spread top with 2/3 cup frosting. Top with remaining carrot cake layer, rounded side up. Frost top and sides of cakes. Sprinkle nuts around top edge of cake to create a 1-inch border. Chill until ready to serve.