Recognize the letters? I pressed them into the band around the middle layer to make an indentation and then popped them off one by one (one has already come off here)
This is what it looks like in the show (the left is when they're being burned into the piece of metal, the right is the rusted metal several thousand years later)
To replicate that, I painted the inside of each indentation with black gel. I think this is one of my favorite elements of the cake
This is the bottom layer. It's got a bit more to be done to it but I liked this bit. :-D
Here's the middle layer after I got the crack in time and space on there and the drop lace with the bow ties. The drop lace is just royal icing thick enough to be piped and hang down from each post (bow tie) without touching the cake or breaking. The smudgy stuff around the crack is luster dust. It was supposed to make it look like light was shining through the crack but it didn't work quite right.
Here is the beginning of the top. You can see the indentations where I traced the designs to be piped on it (my free-hand piping skills leave a lot to be desired)
and after it's all piped. I kind of wish I had done the bottom band a bit differently but it's too late now!
By the way, for those of you who don't know what a TARDIS is, here you go....
It is the Doctor's time machine that travels through space too. BEST. SHOW. EVAR.