It was so much fun to make! It was very time consuming and I am glad I practiced on a smaller cake first. I went for something easy since I am still a cake noob. I just traced Sonic's face, not the whole body. I wrote Happy Birthday on the side and presented it for the one and only person it mattered to: my son. He loved it and was as giddy as... well as a 5 year-old on his birthday!
I wanted to use a lighter colored icing for the background, but the kiddo wanted chocolate everything. The FBCT, however, was made with store-bought vanilla Betty Crocker icing so the food coloring would be at it's best. The cake was a simple Cherrybrook Kitchen Chocolate Cake Mix - allergy free, of course! Peanut Free, Dairy Free, Egg Free, & Nut Free to be exact. Quick review of it: Everyone thought it tasted great! Found it at the local health food store, but I heard Albertson's carried it as well. I used two boxes to make a double layered cake, which it wasn't easy to do with this cake mix considering there isn't much to hold it together. But icing is a nice glue and cover up, so I practiced with it and it turned out nice!
At the party I got a lot of compliments from the parents, even an, "She didn't make that. She bought it." LOL, yes, I did take that as a compliment! Everyone enjoyed it and I was very proud of learning something new (and thankful it turned out well). But mostly, I was happy the kids were really tickled with it.
UPDATE (2-11-12)
I have added the pictures I snapped of my the order of my process:
The image with wax paper on top.
Black icing outline of Sonic's Head (I wish now I did the whole thing!)
Filled in the cream colored areas.
Filled in the green eyes.
Filled in the white areas of the eyes.
Sorry, I skipped some steps in the photos. But Then I filled in the rest of the areas with blue icing and then covered the entire back with brown icing. Then gently smoothed out the back to make sure the icing settled in the empty areas. Then placed the FBCT in the freezer overnight.
For more detailed instructions, please visit Cake Central's "How to Create a Frozen Buttercream Transfer", or check out my FBCT Resources page for links to tutorials and videos.
