Step 6: Dip!
After letting the cake cool for a while, dip them in the icing to give them green tops. You might need to microwave your icing for a little while if it sets too much during this step.
Next add the white chocolate buttons to create the white spots, but make sure to let the icing set for a while before doing this. If you add the buttons too early, they'll go blobby and melt off the sides, but if you add them too late, they won't stick.