I made this Lego Birthday Cake Idea for my son’s 5th birthday. He’s a huge Lego fan and I could tell trying to make and ice a big Lego piece might be a nightmare, so I found some silicone molds from eBay and legos.com and bought Wilton candy melts in red, green, blue and yellow.
I microwaved the melts and put them in disposable bags with a small hole cut at the tip and squeezed the hot candy into the molds. It’s important to pick up the candy mold filled with the hot chocolate, and tap it firmly against the counter top over and over again until all the bubbles rise to the surface and are gone. This ensures a smooth glossy finish and will help keep the tops of the Legos from breaking off. Just as important: the molds with the hot chocolate must go into the freezer and be thoroughly COLD before being popped out of the molds to use for decorating.
I made the candy a few days ahead of time so that the day of the party would be less crazy for me. Then, I just baked two 8″ layers of Duncan Hines dark chocolate fudge cake, iced it in homemade buttercream, let it dry a bit, then used a viva paper towel to lightly smooth out the buttercream. There are lots of tutorials online for this and I recommend them for smooth buttercream finishes.
When the cake was done, I just arranged the Legos around the cake, and used a store bought set of letters for the top since I am not that good at piping words yet. IT was fun and everyone loved it.