This Black, Purple and White Birthday Cake was for my daughter's 12th birthday. She LOVES Justin Bieber so the inspiration were the colors black, purple and white.
The top tier cake was white cake mix from a box. But to keep with the purple theme I added the juice and some squashed bits of canned blue berry pie filling (added about 1/2 cup to the mix and decreased by that much water). I baked it in a 5 inch square pan. It is two layers and I used cream cheese icing in between the layers and to "dirty ice" it.
The bottom tier was devil's food boxed cake mix with chocolate fudge icing. Also baked into a 9 inch square pan--there were two of them also.
We made four batches of MMF: kept one white, one black and 2 shades of purple/violet. The lighter purple was a different store brand gel food coloring, not Wilton but the black was Wilton brand. It took A LOT of black to get away from a charcoal color and to a true black. But I did notice it darkened up with time.
She wanted a checkered pattern on the top. So I rolled out black and purple to about a quarter inch depth. Then used a 1 inch cookie cutter to cut out squares. I thought that I could just stick them on the square cake into the pattern I imagined. But the cake is not exactly square and geometry was not my favorite subject. So you can see the "quilted" like feeling the top tier had. Will not do that again...frustrating to make it meet up at the edges correctly.
The bottom tier was inspired from a plaid hoodie my daughter loves. We used one of those pie crimping roller things to cut strips with the scalloped edge in varying widths and lengths and just tried to replicate a random plaid inspired pattern on the cake. We painted the back of each strip with a bit of water to get it to stick well.
The top border was just extra MMF wrapped like a twist and placed at the margin. The balls were rolled out from the leftovers and placed around the border of the bottom cake. The white balls were dusted with silver dust.
Then vodka was painted onto the white MMF bottom layer to get rid of the bleeding of the darker colors. And then all over the entire cake to make the powered sugar excess disappear.