Prepare 2-layer 9 and 12 in. hexagon cakes and 2-layer round cake (trimmed to 4 in. diameter and to measure 2 1/2 in. high) for
stacked construction. Ice smooth in buttercream.
Prepare round cake for rolled fondant. Reserve a small amount of white fondant to cover top of round cake. Tint 24 oz. yellow and approximately 12 oz. each blue, rose, violet and green. Roll out and cut fondant panels to fit hexagon sides and position on cakes. Decorate panels with tip 2 narrow designs and tip 5 wide designs in royal icing-lines, swirls, dots and zigzags.
Cover round cake with yellow fondant; smooth. Cut white fondant circle with wavy edges; position on cake top. Divide round cake into 8ths, marking 1 1/4 in. from base of cake. Pipe tip 4 double drop strings in royal icing from division points, 1/2 and 3/4 in. deep. Add tip 2 dots at string points. In buttercream, add tip 4 bead bottom border; attach bows. Position candles.
The drop string is traditionally used as decoration on the sides of the cake and is the basis of more ornate string work. Called a "drop" string because the line of piped icing is allowed to "drop" or fall, by itself, before reattaching it to your cake. Pipe a row of single strings or multiple strings in rows of two or three.