Bake a book cake (two cake mixes needed) and place on foil-covered cardboard (attach 3 cardboads together for added strength). Ice with buttercream icing. While icing is still soft, run the decorating comb over the sides of the cake to appear as pages. Pipe borders with tip #20. Pipe writing and stems with tip #1. Pipe flowers with tip #101 and leaves with tip #349. Place cross on the cake, and put a ribbon above the cross to appear as a book mark.