Cut out small square pieces of wax paper. Stick the wax paper on top of the flower nail with some icing.
Fill a piping bag with pink royal icing and attach Tip #104. Hold your piping bag at a 45 degree angle in the center (the wider end of the tip should be at the bottom and the narrow end should be at the top).Make a "loop" with frosting, as shown by the arrows. This will be the first petal.
Repeat Step 2 a few times until you have a full circle of pink petals.You can stop here and make little yellow icing dots in the center. But, if you want a more full and "petally" flower, keep going.
Make another circle of petals by piping "loop" shapes, like you were doing earlier.
Fill another piping bag with yellow royal icing and attach Tip#3.Pipe little dots in the center of the flower.
Push your flower nail into a styrofoam block and let this flower dry for 24 hours or until it hardens completely.
While the decorations are drying, bake chocolate cake and let it cool completely.
Then, ice it with ganache frosting.
Remove sugar flowers from wax paper gently and stick them on top of the icing.
Toss some sprinkles to fill the empty space. Enjoy!