1. Heat oven to 350°F. Line 9-inch round cake pan with foil, extending foil beyond sides. Grease foil.
2. Stir together melted butter, granulated sugar and vanilla in large bowl. Add eggs; beat well using spoon. Stir together flour, cocoa, baking powder and salt; gradually add to egg mixture, beating with spoon until well blended. Spread batter in prepared pan.
3. Bake 25 minutes or until cake is set. (Cake is fudgey and will not test done.) Remove from oven; cool completely in pan on wire rack.
4. Beat cream cheese and powdered sugar in medium bowl until well blended. Beat 1/2 cup heavy cream until stiff; gradually fold into cream cheese mixture, blending well. Spread over brownie layer. Cover; refrigerate at least 1 hour.
5. Remove wrappers from 28 milk chocolates; place in medium microwave-safe bowl with remaining 1/4 heavy cream. Microwave at MEDIUM (50%) 1 minute; stir. If necessary, microwave at MEDIUM an additional 10 seconds at a time, stirring after each heating, until chocolates are melted and mixture is smooth when stirred. Cool slightly; pour and spread over cream cheese mixture.
6. Cover; refrigerate about 2 hours or until chilled. Use foil to lift out of pan; remove foil. Cut into wedges; serve garnished with whipping topping, chocolates and chocolate candies, if desired. Cover; refrigerate leftover dessert. 12 servings.