An 11 year old girl inspired this cake. Back when I would bake cakes as a job, I was contacted by a mother who wanted a gluten-free Doctor Who inspired cake for her daughter’s birthday party. Having heard good things about my work and cautiousness with food allergies, she contacted me and booked me to make the cake. I honestly didn’t know what I would be getting into.
I started by looking for inspiration and I spied a 3D Doctor Who Tardis cake among the flat cakes, and I knew I needed to make *that* cake. For those of you unfamiliar with the show, the Tardis is the iconic blue police box in which the Doctor and his companions travel. When I delivered the cake, the party was set up with some pretty awesome decorations, and the birthday girl was thrilled with the result. I, perfectionist that I am, was not 100% happy and promised myself I would improve and make it again. But first, I had to see what this Dr. Who mania was about. The Godfather and I began by watching an episode of the reboot on Netflix, and then another, and another… and soon we had watched all the episodes currently available on Netflix for both the reboot and the original series! We don’t have BBC, so we are patiently awaiting the release of the latest season with the twelfth doctor. I suppose somewhere along the way, we became Whovians! 😉
Anyway, the re-creation of this cake had been weighing on my mind for some time, and after we finished the last of the classic episodes, I needed a Doctor Who project, and making the Tardis Cake tutorial seemed fitting. This is long, and the making of the cake itself takes some time, so grab a cup of tea or something and then come back because there’s a lot to learn here.
First off, let me say that this cake is also not good enough for me because I rushed some of the final details thanks to a mishap with cheap chocolate and a ganache that literally started melting off the side of my cake. Let me explain how while sharing a few basic tips about the cake’s construction.
You’ll want to use a more dense cake recipe. Something too airy and spongy will not hold the weight of the decorations and the shape well at all, even with supports.
Because this cake takes some time to assemble, I personally would not use highly perishable fillings and would avoid jams and jellies because they might cause the cake to slide and shift. I used a chocolate hazelnut spread for this cake.
The Frosting (and where things went a little wrong for me)
You may use a butter cream frosting, but I recommend a chocolate ganache. Chocolate ganache works beautifully under fondant to create very sharp edges, which you want when you are looking to make the Tardis cake. It is a police box after all, and it’s much easier to apply the fondant cleanly with ganache, especially at the corners.
I opted to make a white chocolate ganache with a 3:1 ratio (three parts chocolate to one part heavy cream by weight), which experience has taught me works well. The problem arose when I grossly miscalculated the amount of chocolate I would need and I ran out mid cake! The closest store to purchase my preferred chocolate is 20 minutes away, so I popped over to a closer store and picked up some white chocolate thinking “this will do”, and it did… the first time (oddly enough, when I used chips from a very common national brand). The second time I ran out, I picked up a different brand, a baking bar I hadn’t seen at the first store and thought, “this will be better, there isn’t any coating to deal with so maybe it will melt like my better quality chocolate”, and the ganache did not set. At all.
It appeared to set enough that I could spread it on the cake, and after chilling, it again had the appearance of being just set enough to work, but the moment I applied the fondant and went to go cut the embellishments, leaving the cake on the counter, I noticed part of my fondant was literally MELTING off the side of the cake in a disastrous runny ganache avalanche. Given that I had made each side level-straight, and the fondant lined up so beautifully at each corner, I just about lost it. It was bad. So bad that it’s been a few months since I made that cake and I needed to come to terms with this chocolate situation before I could rationally speak about it. Excuse my while I collect myself for a moment.
In this situation, I fixed it, and ended up removing huge portions of the fondant around the melting ganache, scraping it away, and then re-building as best I could with a crusting buttercream. But it threw off my schedule so much, that I was rushing, in the middle of the night, to finish the details so I could photograph early the next morning and ship the cake off as a Friday treat to the Godfather’s office. Who, by the way, didn’t cut into the cake at all because no one wanted to mess it up. Apparently, people just stopped by to admire it throughout the day and bemoan the fact that they can’t have cameras at work to take a picture. So it was going to sit, neglected, over a weekend in the office fridge after all that work! Thankfully, we were able to send it to a local college basketball team’s game with a co-worker of the Godfather’s, and hungry college athletes have no such qualms about cutting into something when Nutella and cake are involved. For that, I am grateful.
The moral of this story is… do not use cheap chocolate because you end up with bad ganache, which will make you cry. Cheap chocolate makes you cry. And if you’re making this for someone you care about, they’re worth the good stuff.
So as you can see, in the rush and late night decorating, I didn’t have enough time to properly clean up all the little details and make this as perfect as I wanted, but these are my personal hang-ups, not yours, unless you’re like me, and then you understand. But the instructions are clear enough that you should be just fine. 🙂
HOW TO MAKE A DR. WHO TARDIS CAKE:
List of Materials:
- 2 6″ square cake pans with straight sides
- 3-4 lbs chocolate for your ganache (if using), or 10-12 cups of frosting
- 2 lbs blue fondant – I used Satin Ice
- a bit of white fondant
- a bit of black fondant
- a fondant smoother
- a cake turntable
- cake leveler
- disposable piping bags
- Size 2 piping tip – you’ll get the best price at your local craft store
- Milkshake/Bubble Tea Straws or Cake Supports
- a paper lantern party light
- plastic wrap
- wax paper
- royal icing
- a fondant mat
- a fondant roller or large rolling pin
- pearl dust (optional – for cake board)
- a pizza cutter
- a plastic ruler or straight edge
- a level (washed very well if it’s not dedicated for food use)
Start by baking your cake layers. You’ll need enough for 8 1-inch tall layers. I accomplished this by baking four six inch by two inch pans and torting them. I do not recommend the pans I used, and I explain why in the first video below. I recommend a pan like this one from Fat Daddio’s, I’m actually purchasing these very pans for myself to replace the ones I have.
You’ll also want to prepare your filling and frosting. If you are making a chocolate ganache, use 48 ounces of chocolate (3 pounds), assuming you have something else for the filling. Make 64 ounces (4 lbs) if you are using the ganache to fill the layers as well.
If you are using white chocolate, as I did, use a 3:1 ratio of chocolate to heavy cream. A 2:1 works for milk chocolate, and a 1:1 for bittersweet. This is a LOT of ganache, so use a large bowl and allow it to set for several hours or overnight. You may also make it in two batches as you work on the cake.
If you haven’t purchased a 6″ square cake board, like this one here, you’ll need to cut one from a larger board. You will need two, one for each tier. You’ll also need a larger, sturdy cake board for final presentation. I didn’t have a thick one on hand, so I used two of these basic cake boards stacked together.
Preparing the Cake Board
You can prepare the cake board a day or two in advance so the fondant can dry and set before you add the cake. I chose to finish this cake board with a space/galaxy inspired look. I achieved this by taking some of my blue fondant, black fondant, and a bit of red fondant I had on hand, rolling them into snakes, twisting the snakes together, and then rolling and folding as needed to get the effect I wanted. Just be careful not to fold too much or the colors will completely blend together.
I brushed some water very lightly on my cake board to help the fondant stick, rolled my fondant just slightly larger than my board, and then using firm pressure and my fondant smoother, affixed the fondant to the board, paying special attention to the edges so there was a good seal. Then use a pizza cutter to trim the fondant to the size of the board and set aside. I also brushed the board with a little super pearl luster dust to give the effect of stardust.
Torting and Filling the Cake
It’s easier to just explain this, so I made a video for you! If you are already comfortable with splitting and filling cake layers, move on to the next section.
Covering a Square Cake with Ganache
The same basic technique applies to buttercream. This is the easiest way to get nice sharp corners and straight edges. I also show you how to ensure you have a nice level top. Pay attention to the hints I provide in the video regarding the top layer. I didn’t, and separating the top board from the cake was challenging and resulted in a top that, while even, wasn’t as pretty as it should have been.
Stacking the Tiers
It’s very important to have proper supports for your cake! One of my biggest pet peeves for tiered cakes is seeing the top tier sinking into the bottom tier, especially when they come from a bakery. It just doesn’t look professional, especially when it’s just a two tier cake.
It also reminds me of one time when I built a topsy turvy cake (I was so proud of it!), but I used a less-dense cake recipe and didn’t support it just right, and the cake buckled under its own weight several hours after completion. I have probably an unhealthy amount of residual guilt over it even now. Don’t make this mistake.
This handy little video will show you how to make an extra-sturdy Tardis cake. I even test it for you at the end. 😉
Adding the Fondant
Here’s where we don’t have anymore videos. I expected to place the base fondant, then video adding the details, but we had the aformentioned Ganache-pocalypse and between fixing and the late night work, the video just wasn’t happening. If you have questions, contact me and I’ll walk you through it. 🙂
For me, the easiest way to add the base fondant to the sides and top was to measure the dimensions and cut rectangles and squares of fondant to fit. It’s an easy shortcut to ensuring corners stay sharp, and since you’ve already put the work into creating level and even sides, it’s the easiest way to apply all that fondant! My frosted cake was 21 cm tall by 15 cm wide. Centimeters were easiest to use in measurements for all the detail work.
Since your ganache is set, you’ll need to spritz your fondant with a little water or simple syrup, or brush it very lightly with some piping gel to give the fondant something to stick to. Place each rectangle, and the top square carefully, without stretching, and then use your hand, and then the fondant smoother to affix it firmly to the cake and smooth together the corners. They should fit together rather perfectly.
After I finished this step, we had the ganache meltdown (literally) on two sides and I had to remove one and a half sides of fondant and ganache, replace with a crusting buttercream, re-cut fondant to fit, and move forward from there. Very stressful and entirely too time consuming. So don’t do that.
Now is a good time to attach your cake to your prepared cake board. Do so by placing the cake on the board and running a pointed dowel all the way through the cake and board together. You’ll have a little hole up top, but you will be covering it later anyway.
Next, it’s time to cut out the details. You will need four black rectangles 14.5 cm wide by 1.25 cm tall. These are the background for your Police Box signage. Cut them out and use stiff white royal icing to pipe the letters. Set these aside to dry overnight.
Cut the center columns. To get perfectly straight lines down the center cut four 20 cm long by 4.25 cm wide strips. find the center top edge of your first side of cake and apply the column with the short end aligned to the top edge of the first side. You’ll have a gap at the bottom, but that’s fine as you will cover it later. To get the center partition and make the “doors” for the front of the Tardis, place your ruler’s edge along the center of the column and press gently to make a straight impression. Add the door handle with royal icing.
Cut 8 7.5 cm long by .5 cm tall strips and position them evenly along the sides of the Tardis, using water or piping gel to affix. If your cake is the same height as mine, the measurements for each strip starting from the bottom are 5.5 cm, 10 cm, 14.5 cm and 19 cm. The Godfather was very particular about getting the cake to scale, for which I am thankful.
Next, cut the two columns for the corners. These are 1 cm wide and 21 cm tall. Apply these along each edge for the side you are working on.
Note: If it hadn’t been so late and I hadn’t been rushing, I would have taken the time to trim the existing lines so there are no bumps!
Repeat this process, except the door seam impression, for the remaining sides.
Add the windows by cutting 8 2.67cm square pieces of black fondant, rolled thin. Gently place them into the appropriate openings on each side of the cake, and add panes using royal icing.
Roll out another 2.67cm square of white icing, and use an edible ink marker to add text. Fit this into the corresponding box on the front side of the Tardis.
Roll fondant a little thicker than usual for the bottom border (I didn’t measure how thick I rolled it) and cut four columns of 15 cm wide and 1.25 cm tall. Attach these along the bottom edges of your cake, using the heat of your hands to bring the corners together.
When the Police Box Signs have dried, cut out four 1.5 cm tall by 15 cm wide blue fondant rectangles. Using a bit of royal icing or piping gel, apply a black plaque to the center of each blue rectangle. Use piping gel or royal icing again to affix the signs along the top edge of each side of the cake.
FINALLY, it’s time to add some special effects!
I like to use a party balloon light at the top of the cake as my only non-edible decoration. This detail must be added close to event time as the lights only last a few hours.
First, make a fondant pyramid to act as a base for the light. You may either make this as large as the top of the cake, or smaller as I did here. The style varies slightly by Doctor anyway. Twist the bottom of your light to activate, then wrap in plastic wrap. Press the light into the pyramid so the base is covered, and add a small dot of fondant at the top of the bulb to represent the light casing.
And you’re done!
To cut the cake
The easiest way to cut this cake is to remove the light, pull out the center dowel, separate the tiers, and cut. This cake feeds 20-25.
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