I used English tea cake (I thought the 'English' part was rather appropriate) for the cake itself, and was lucky enough to have a TARDIS-shaped cake pan! I didn't cut the cake this shape, although I did make the top of it flat, then flip it over so the part I ice is flat and the bottom (which was the top) can sit without wobbling all over the place.
Once I'd cooked the cake, I mixed up some vanilla icing and added blue food dye. I found that the first time, I didn't make enough icing, so I had to re-mix some and add the food dye again. It wasn't easy to get the same shade of blue, though I got pretty close!
Something I didn't anticipate though - once the cake was complete, and everyone had a slice, I realised that it's a good idea to read instructions on packets. It said how much food dye to use, but I decided it shouldn't matter how much you use, and used a bit too much. Therefore, when people ate the cake, their teeth went a lovely shade of blue! Everyone said it tasted delicious though, so I was forgiven. :P
I wanted to write 'Police Public Call Box', but quickly realised that writing with (very yummy vanilla fudge) icing isn't easy, so I could only fit 'Police Box". I also wanted to do the little light on top of the TARDIS, but that would make things too complicated for this novice. :P
The TARDIS cake was then joined by some familiar face (yes, I'm a dork) - the tenth Doctor in his suit from 'The Impossble Planet'/'The Satan Pit' and Captain Jack with his clothes from 'The Empty Child'/'The Doctor Dances'. The Doctor has a helmet, and Captain Jack has a hat, but they seem to have disappeared. Oh, and they're actually my little sister's figurines, not mine. The sonic screwdriver (you can't see it here) is mine though!
TARDIS, complete with birthday candles! I've promised my other sister that for her birthday, I'll make her a Dalek cake - that will definitely be interesting!