Preheat oven to 350°F. Lightly spray pans with vegetable pan spray. In small bowl, combine flour, baking soda, baking powder and salt; mix well. In large bowl, cream butter and sugar with electric mixer until light and fluffy. Add eggs; beat until combined. Add chocolate and vanilla; mix well. Add dry ingredients in thirds alternating with buttermilk, beating after each addition until smooth. Pour batter into prepared pans.
Bake 25-30 minutes or until toothpick inserted into center comes out clean. Cool in pan on wire rack 10 minutes; remove from pan and cool completely.
For ganache, heat whipping cream in saucepan just to boiling point. (Do not boil.) Remove from heat, add chopped Candy Melts; stir until smooth and glossy. If mixture is too thick, add 1-2 tablespoons additional whipping cream. Stack cake layers on cake circle; pour ganache over cooled cake.
Top with Candy Clay Roses.