First, consider the elderly standby. A simple cake should work for this one, but have the number 40 written as big as feasible. Then, surround the edges of the cake with 40 candles. Don’t forget to light them. & don’t forget to have a fire extinguisher standing by. A 40th birthday is a lovely time to celebrate! If you’re going to be throwing a party for somebody who is reaching that milestone, here are some 40th birthday cake ideas for fabulous cake possibilities.