Assemble treat pops. Prepare buttercream icing following recipe directions. Tint violet, green, yellow, rose and orange; reserve some white.
Push cake round into bottom of treat pops container. Use tip 12 and the same color icing as cake used to pipe a swirl of icing from back edge following the curve of the container, then filling in the center. Repeat to add four more layers of different color cake and icing layers. Position cupcake on top. Use tip 12 and white icing to pipe a swirl on top. Attach cinnamon candy on top with a dot of icing.