I first saw this idea when I stumbled onto this cake from Glorious Treats. I absolutely loved the idea and just had to try it out for myself. Turned out pretty well I'd say!
It was actually super easy, just a little bit time consuming. For the cake batter, all I used was two boxes of white cake mix. I prepared it according to the package instructions but added food color to get red and blue colored cake. I used all the batter from one box to make the red, plus a little added from the second box. Then the remaining was half blue and half left white.
Assembly is pretty easy, the only layer you actually have to cut into is the top. The circles can be cut by using a cookie cutter or a glass to imprint the right size, followed by a knife to cut it out with. After baking and assembling, you will have a red outer circle ring and a blue inner circle. You can obviously do whatever you want with the remaining cake, but my suggestion would either be to mix it with some frosting and make cake balls, or just eat it. Probably just eat it.
For the decorations on top, all I did was melt red, white, and blue candy melts inside of a disposable plastic bag in the microwave. Now when you're doing this, only melt for maybe 15 seconds at a time, then take the bag out and knead the chocolate together before placing back in the microwave. When its melted throughout, snip the corner of the bag and drizzle squiggles onto a lined sheet of wax paper. Refrigerate until set.
The idea behind the chocolate squiggles was to resemble fireworks a little and capture the overall excitement of the 4th of July. I also added sprinkles! While I was assembling, yes, many of the chocolate squiggles broke, but I had made plenty to replace the broken ones with.