What you need:
1 cake mix
1 can frosting
1 tube decorating gel
One 8-inch round cake pan
Mix the cake following package directions and bake one 8-inch round layer and 12 cupcakes. You will need 2 cupcakes for the carriage wheels; the remaining 10 can be decorated with the baby's initials or birth date.
When the cake is cool, cut a 3-inch-wide wedge from the cake and remove it. Place the 2 cup cakes below the round layer. Frost the entire shape. With decorating gel outline the carriage shape and add radiating lines for the carriage hood. Draw the wheels and spokes. Write the baby's name and birth date on the body of the carriage.
Also, you can't have a great cake without a great matching baby shower centerpiece.