Melt yellow and white candy melts, separately, at 50 percent power in the microwave, until completely smooth.
On a parchment-lined baking sheet, spoon mounds of white and yellow candy melts on top of each other, leaving about two inches between each multicolor mound.
Pull the wooden skewer through each mound, to marbleize the melts and create “sunburst” shapes.
Allow the sunburst shapes to dry completely before peeling them from the parchment.
Using a little buttercream, attach the sunbursts onto the iced cake, all the way around.
Create height by pressing more shapes gently into the top of the cake, all the way around.