My son wanted to have a Wizard101.com cake since he plays the game a lot. So I thought..wizards...um...castle? A friend of mine told me how to do it.
You need 3 cake mixes 2 or 3 cans icing (depends on how heavy you want it) package of sugar cones gum drops wax paper skewers (to hold towers up) 5 soup or veggie cans label removed and can washed & 1 lid 1 9x13 pan 1 square pan (think it was a 9") 1 round 9" pan food color to make color of icing as you like it Baker's Joy (spray with flour...but you can use plain spray too)
I personally used vanilla icing and black food coloring and it was a dark gray after adding LOTS of food color (like 100 drops!!). Due to it being a migraine trigger, I cannot have chocolate so therefore I colored the icing as dark as I could. To get black icing I've heard you mix the black food color with chocolate icing. Now it's all over I probably could have used caramel icing and gotten closer to black instead of gray.
Bottom layer (mix #1) is the 9 x13 iced that while square pan (half of mix #2) was cooking, then after square cooled put it on top of 9x13 cake but twisted it and cut the overhanging corners off. Then I iced the square while the round pan (other half of mix #2)was cooking. 3rd layer is the round pan which I placed on top and iced it. (my kids said it looked like a tank without the gun barrel at this point LOL). Now comes the tricky part.
Using the can lid, trace 5 circles on wax paper and cut out. After cutting, I sprayed the bottom of the can then pressed the cut out circles to the bottom then sprayed the top of the circles. I then cut out strip of wax paper long enough to go around inside of can plus a tiny bit. I again sprayed the can inside then placed the wax cutout then sprayed the wax paper cutout. I used one of the skewers to press it into place near the bottom. Then fill each about 2/3 way full which using green bean cans takes a whole cake mix. Place all 5 cans on cookie sheet and bake at 350 for about 25 mins (depends on oven). pulled them out and should NOT HAVE layed them on their side, each tower had a flat side. So they need to cool standing up. I then attached them one to each 4 corners plus 1 in middle and iced them too.
For the cones it was easier for me to hold the cone and "finger paint" the icing on them. If skewers are too tall use heavy duty scissors to snip to height needed. I used a toothpick to draw the stone looking bricks. Gum drops around the round pan.
I used leftover wax paper and pressed 5 gum drops flat then rolled each onto tooth pick and inserted into top of cones (might need to trim bottom of cone for it to fit).
I then just piped kid's fave color around edges of cake and wrote Happy Birthday on side.