Melt yellow Candy Melts. Lightly sprinkle black sugars over prepared pattern; with melted candy, outline and fill in pattern. Smooth with spatula. Let sit until surface of candy looks dull, about 5 minutes. Position cupcake piece on one half of candy; lift waxed paper to fold candy over cupcake piece to form the shell (keep waxed paper on candy). Place in refrigerator until set, about 5 minutes.