This topsy-turvy cake makes a dramatic centerpiece for any party, but it would fit in especially well with a Mad Hatter's theme. The vibrant colors on our cake were created with gel food coloring, available at many grocery and craft stores. Follow label directions. Idea from Anita M. of Taylor, MI.
If needed, trim the top of one cake of each size with a long serrated knife to make it level. Stack the same-size cakes to make the three layers: spread a thin layer of white frosting on the trimmed side of one cake, then top with the matching cake (flat sides together). For a smooth surface, prepare the cake layers by spreading a thin layer of white frosting around the sides. Put them in the refrigerator for 30 minutes to set.
Use the serrated knife to cut each layer of cakes at an angle, as shown. (You can save the scraps for snacking.)
Place the 10-inch layer on a serving platter and place the 8- and 6-inch layers on the cardboard circles. For stability, press 3 straws each down through the centers of the 8-inch and 10-inch layers (a triangle pattern works best) and trim the straws so they're level with the top. Spread the tops of all three layers with white frosting.
Before assembling the cake, cover the sides of each layer with the colored frosting (we show it with only white frosting for clarity). Frost the 10-inch layer with pink, the 8-inch layer with yellow, and the 6-inch layer with green. Spoon the rest of the colored frostings into pastry bags. Stack the 8-inch and 6-inch layers on top of the 10-inch layer so that they are tilted but balanced.
Spoon the remaining white frosting (about 3/4 cup) into a pastry bag fitted with the star tip. Pipe a decorative border around the base of each layer. Use the same tip, rinsing after each color, to pipe pink, yellow, and green borders around the top edges of the layers, as shown. Use a small round writing tip to pipe decorative lines, circles, curlicues, and dots. Serves 36.