Beat butter, sugar, eggs and vanilla; set aside. Combine flour, cocoa, baking soda, baking powder and salt; add alternately with water to butter mixture. Fill paper-lined muffin cups half full. Place a chocolate drop in center of each. Bake at 350 degrees for 20 minutes. Let cool. To prepare Chocolate Frosting combine all frosting ingredients; beat until smooth. Frost with cupcakes Chocolate Frosting. Top each with a chocolate drop.