1. 1. Heat oven to 350 degrees. Butter three 6-inch round cake pans. Line bottoms with buttered parchment paper and dust with flour.
2. 2. Sift together flour and cocoa twice. Melt butter. Dissolve espresso in hot water; add with vanilla to butter. Keep warm.
3. 3. Break eggs into a large bowl and add sugar. Whisk over a pan of simmering water until warm. Remove from heat, and beat on high speed until tripled in bulk.
4. 4. In 3 additions, sift flour-cocoa mixture over egg mixture, folding quickly but gently. Scoop a cup of the batter into a small bowl, fold in hot butter mixture, and then fold back into rest of batter. Divide evenly among pans and bake 20 to 25 minutes. Cakes will shrink away from sides of pan when done. Cool in pans 5 minutes, then turn out onto a rack to cool completely.

Assembly

1. 1. Trim off tops of 2 layers; moisten cut sides with Coffee Syrup.
2. 2. Top 1 trimmed layer with Mocha Buttercream.
3. 3. Add second trimmed layer; cover top with Mocha Buttercream. Add untrimmed layer. Chill until firm.
4. 4. Using serrated knife, carve edges of top layer to make a dome shape. Frost cake with Meringue Buttercream. Chill again.
5. 5. Divide remaining Meringue Buttercream among 5 bowls. Tint 4 with rose, lavender, blue, and green Ateco paste food coloring. Leave fifth plain; fill sixth bowl with Mocha Buttercream. Cover cake with lavender frosting. Chill. With a toothpick, trace 6 large shell shapes around cake. Using a #1 plain tip, pipe rows of plain, mocha, blue, and rose frosting inside shells. Pipe a thick scalloped rose line on top of outlines. With a pastry brush, brush downward to blend inside colors. Using a #100 tip, pipe green lines between and over shells, overlapping on top of cake. Using a #70 leaf tip, pipe green and rose leaves on top. With plain tip, pipe green vines around bottom. Using a #67 tip, pipe on leaves.