My son who was turning 5 years old really wanted a pirate birthday party. I had made my older son a pirate ship cake for his pirate themed party and wanted to do something different. I decided a Pirate Treasure Chest Cake Design would be perfect. Since my son was born on my brother's birthday, they usually share a party. Sometimes I make them separate cakes, but this year I said the 5-year-old could have the treasure chest and the 20-year-old could have the cannon ball.
The first thing I did was bake 5 layers of cake. To make it more interesting, I baked 4 different flavors, strawberry, white, yellow, and chocolate. The bottom of the chest was 3 layers. The lid was 2 layers that I rounded to make the right shape. The icing was butter cream that I added cocoa powder to so it would be chocolate (and brown). I left lines and didn't smooth it out perfectly on purpose to make it seem "older".
I added black icing coloring paste to some of the icing to make the bands around the chest, the handles on the sides, and the keyhole. The lid was on two hinged boards so that it would open and close. One part of the board was on top of the bottom layers of the chest and the other was supporting the lid. There was a hole in the bottom of the board so we could fit candy coins, gold nuggets and necklaces down inside the cake and pouring out of the chest.
I covered the boards with aluminum foil to look like the chest lining (so you couldn't see the wooden boards). The cannon ball was chocolate cake that I baked in a bowl and then carved a little to make it the right shape then covered with chocolate icing. The whole cake was so heavy that I put it on a 1 inch thick piece of plywood covered with fancy foil wrap that I had left over from a wedding cake. I spread chocolate frosting on the foil and sprinkled it with crushed Nilla Wafers.
I placed novelty candles from a party store and dropped candy all around the "sand" to complete the look. This cake was enormous and a huge success. Everyone at the party loved it!