Special Equipment: 1 1/2-inch thick wooden dowel (10 inches long)
1/2-inch ribbon (48 inches each pink, mint, lavender and yellow)
Hot glue gun or tape
1/4-inch star pastry tip
Secure a colored ribbon with tape 4-inches from the bottom of dowel. Flip dowel upside down and twist the ribbon around and down the dowel (there will be excess ribbon at the end). Secure ribbon at the top of the dowel with tape or glue. Repeat with the rest of the ribbons.
Place 1 cake layer on a glass cake plate. Spread top with lemon frosting and top with the second cake layer. Frost the entire cake with 2 containers of vanilla frosting. Set aside.
In a small mixing bowl, combine 1 container vanilla frosting with 3 drops red food coloring and 1/4 teaspoon strawberry extract to make pink frosting. In another bowl, combine 1 container vanilla frosting, 3 drops green food coloring and 1/8 teaspoon mint extract to make green frosting. In a third bowl, combine 1 container vanilla frosting, 4 drops red food coloring, 2 drops blue food coloring and 1/4 teaspoon cherry extract to make lavender frosting.
Make a pastry bag by cutting a small triangle out of the bottom corner of a large zip-top bag. Place a star pastry tip on the inside of the bag and fit tightly into the hole. Place pastry bag, tip down into a large drinking glass. Place a large spoonful of each color of frosting along the sides of the pastry bag. Remove bag from glass and, starting from the top, squeeze frosting into the tip. Pipe a colored border around bottom and top of vanilla-frosted cake. Pipe the colored frosting on the cupcake tops in an upward swirl motion.
To assemble centerpiece, place cake on table. Insert the bottom end (without the excess ribbon) of the dowel into center of cake. Pipe colored icing around bottom of dowel. Carefully lay each color of ribbon on the table and arrange cupcakes at the ends of the ribbons. Tie the ends of the ribbons in bows and trim off the excess.
Place more cupcakes on top of the cake. Decorate the whole cake with some edible flowers.