I got so many great ideas from this site that I had to share my results of my Princess Castle Cake.
I used the double stacked ice cream cones to make the four tall towers and then single cones for the shorter towers. I dipped them in purple colored chocolate. I dipped them twice and I regretted that part. The first layer got "chunky" looking with the second dip. Next time, I will only dip them once.
However, I dusted them with purple pearl dust and the shine made a big difference. For the roof of the turrets, I used sugar cones dipped in white chocolate and then coated them in Silver Luster Dust. In hindsight, next time I will make small holes in the cones to hold flags. After they were dipped in chocolate it was very difficult to put a toothpick/flag through the top without breaking the cone.
I made the towers a couple of days before. Also, I wish I had drilled/poked holes through the tower cones to use dowels for stabilization, as the cake had to travel a good deal. Originally, I had planned on a full tower on the top of the cake instead of just the tower roof- but I couldn't get it to travel well.
The cake was two main layers of a 9*9 white cake and then one layer of an 8X8 white cake. I trimmed the corners to fit the towers. To add height, I split each of the layers to make mini layers with icing in between. The pink is butter cream icing, as in the green and purple trim. The grey windows and drawbridge are from marshmallow fondant I made.
As a Christmas gift I got a Wilton Castle Cake set from a family friend. My daughter saw it and being the princess that she is, instantly wanted a Princess Castle Cake for her 4th birthday party. The kit came with plastic windows, a plastic door, and the plastic pillars.
I made the larger cake on the bottom vanilla, and the top tier chocolate. They both had butter cream icing in between the cake layers. About 2 weeks before I baked the cake I prepared all of the fondant flowers. I purchased already colored fondant, used a flower cut out and then pressed the centers to make the flower shape. I put a dab of white icing in the center of each one. I froze the flowers until I was ready to put them on the cake. I used dowels in the bottom tier to help support the weight of the top tier and placed the top tier on a plastic cake plate for easy disassemble.
I covered the entire cake in white butter cream frosting. I then decorated the plastic pieces that are pink with pink icing and dipped it in pink edible glitter. I added all of the plastic pieces to my cake. I then piped on the green icing to create leaves and stuck the flowers to the cake. I piped her name on top of the cake in pink icing and dusted the top with the pink edible glitter.
My daughter loved her castle cake for her birthday!