For my sons 4th Birthday we chose the Star Wars theme.  I mean how cute would “May the Four-ce be with you” be?  As a caker I had so many ideas for the cake.  It was quite overwhelming actually. I wanted to try to tie the old and new Star Wars movies together. So for the actual cake I just air brushed the cake to look like a galaxy far far away.  Here is a pic of the final product.  

You will need an: 

Airbrush Machine

Food coloring/gel/airbrush colors in Blue, Black and Purple

Vodka (if using food coloring/gel)

Cardboard Box

Cake Turntable (optional) makes the process a little easier/quicker 

I used the Cake Boss Airbrush machine. I was so reluctant to purchase it because I always felt it wasn’t a necessity but after using it my first time I realized how much quicker and cleaner it made the cakes look. My sister actually purchased mine for me (she gets free cakes whenever she wants).  You can purchase one Here. 

For the colors I used purple, black and blue food coloring.  I had to thin them out with vodka in order to use them in the air brush machine. The machine comes with a little liquid dropper.  I filled the little resovoir with my first color blue and just sprayed it here and there on the cake making sure to move the cake often on the turntable. Then went on to the purple then black. I repeated this process with the colors until I felt it was dark enough. Between both tiers it took about 30 minutes. 

I apologize for not taking more pics as I was spraying away I got really into it and found it almost therapeutic and zoned out. 

After you feel you have the desired effect you wanted you can also makes “stars” in your galaxy by taking white food coloring and a paint brush and splatter away. 

Here is a helpful tip, take a cardboard box and try to make a boxed in area to keep the color contained. There will be color EVERYWHERE!! I used a cake board box and made a little contained area.  
This is the pic of the final product with the Death Star topper and some figures. 

The death star was made from RIce Krispy Treats which I sculpted and covered in fondant the decorated. I cheated a little and made BB8 from styrofoam balls (cut the smaller one in half for the head) covered in fondant then decorated. R2d2 was made from RKT as well covered in fondant then decorated. I sculpted Kylo Ren and Logan Solo instead of Hans lol. 

The cake was a big hit, everyone loved the decor especially the birthday boy.