How to make a Warhammer Purity Seal Cake

I’ve been a mum for 12 years now, and for about ten of those years, I’ve asked my son what kind of cake he would like for his birthday. I’m no Mary Berry, but I can knock up a good sponge cake, and I’m happy to give pretty much anything a go. Over the years we’ve had a volcano cake, a train cake, a Minecraft block and a Pokémon cake, amongst others. This year he asked me to make him a Warhammer purity seal cake, so I gave it my best shot.

Whilst not wanting to diminish my son’s latest obsession, Warhammer is basically painting tiny figures and then having a ruckus with your mate who also has some painted tiny figures. It’s a world I don’t fully understand, but I don’t need to understand it, I just need to continue to fund it.

How to make a Warhammer Purity Seal Cake

In essence the cake is three layers of Oreo sponge, with Oreo frosting between the layers and all over it, which make it look like a muddy battlefield. After tapping into the expertise of a Warhammer loving adult, we brainstormed some ideas. My friend did the hard work, the painting and his painted creations would also double up as birthday gifts for the birthday boy. My role was to make the cake, and the paper scroll for the purity seal.

To make the purity seal

This was a two part job, with my friend ordering a 3D printed purity seal coaster off Etsy and painting it up accordingly, and me creating the scroll. I did this using an app called Canva, which is free and I use it quite a lot for various design things. I added his name and some appropriate Warhammer words and logos, then printed it on cream paper. The font I used was IM Fell English SC, which was as close as I could get to authentic. Aging the scroll meant dabbing the paper with a damp teabag, which worked well.

purity seal

Once dry, I lit a candle and carefully (VERY CAREFULLY) held the paper above the flame to give extra colour and raggedy edges to the scroll. Be careful not to actually burn the paper. I made sure I was doing this on a flame proof chopping board, so if it did go up in flames, I could put them out quickly. Together with the appropriately painted seal, it looked pretty darn good.

If you want to read more about the painting of the purity seal, you can do here.

How to make a Warhammer Purity Seal Cake

To make the Oreo cake

For his birthday, I made two of these cakes as he was having a family party and a party with friends. Click here to go to the recipe for the Oreos cake. You can make the sponge layers in advance. As long as they are well wrapped up, they will be fine for a day or two. The vanilla frosting is meant to look like a muddy, gritty battlefield, the kind a troop of Space Marines might find themselves on. The trick is to not overmix it, or it just becomes a dirge colour and not speckled. Don’t forget to save an Oreo or two to crumble up as extra dirt on top of the cake.

Follow the instructions on how to put the cake together, once you’ve got your Oreos cake built, it’s time to decorate it!

How to make a Warhammer Purity Seal Cake

To decorate your Warhammer Purity Seal Cake

You will need a couple of toothpicks to hold some of the decorations in place, so don’t forget they’re there when it comes to serving your cake! Decide where you’re going to place your purity seal and using half a toothpick, pin the paper scroll in place. Using some of the Oreo frosting as glue, stick the purity seal down, on top of the cake, at the top of the scroll.

We also had a painted Space Marine to top off the cake. His base had been sculpted at the bottom so you could stick a toothpick in and anchor him into place, which was a stroke of genius. Around his feet I sprinkled some crushed up Oreos, which made him look like he was wading through mud.

How to make a Warhammer Purity Seal Cake

As it was a birthday cake, I ordered some black candles, which finished it off nicely. My son absolutely loved his birthday cake and was impressed by how good it looked. If you’re into Warhammer and Oreos, then this is a relatively simple cake to put together, if you’ve got someone doing the painting for you that is!

It’s a brutal looking cake, but it really was delicious!

How to make a Warhammer Purity Seal Cake

Recipe: Oreo cookies and cream cake

My son loves Oreos. They’re the thing he asks for when we need him to do something he doesn’t want to do, like take some medicine, or finish his French homework. So when it came to his birthday cake this year, he asked me for an Oreo cake, so I took to my kitchen, got experimenting and came up with this simple recipe for a three layer Oreo cookies and cream cake.

There are a lot of Oreos in this, and as we are trying to cut costs a bit, we used the Aldi version at a fraction of the cost. They’re really no different at all. I’ll leave it up to you if you want to use the real ones or the supermarket versions. This cake including the frosting used 5 packs of Oreos, which is slightly terrifying. You could use a little less if you feel that might be the right thing for you and your cake. 

Recipe: Oreo cookies and cream cake

For the frosting, I did experiment with making Oreo buttercream with butter, icing sugar etc, which worked fine, but the pre-made vanilla frosting really tasted like the inside of an Oreo, spread much more easily, and was just so much better in terms of flavour and texture. My advice would be to use the pre-made frosting and just stir the crushed Oreos through it.

If you usually make your cakes using a mixer, that’s fine, but I’d urge you to just fold the crushed Oreos through the cake batter, as mixing it with the food mixer changes the texture and look of the cake. It’s darker and denser, and somehow less appealing because of that. This is a three layer cake, because it was a celebration cake, if you want, you can cut the recipe by a third and make it a two layer cake and that’s fine too.

Oreo cookies and cream cake

Ingredients:
300g caster sugar
300g softened butter or margarine (I use Stork)
6 eggs, beaten
3 tsp vanilla extract
3 tbsp milk
300g self-raising flour
1.5 tsp baking powder
300g crushed Oreos

For the frosting:
600g vanilla frosting, I used M&S
200g crushed Oreos

Recipe: Oreo cookies and cream cake

Method:

Heat your fan oven to 190c. Grease three 20cm sandwich tins, I also lined the bottom of each tin with a circle of baking parchment. In a large bowl, beat your butter and sugar together until fluffy (I used a hand mixer). Add the eggs, milk and vanilla and combine, then add the flour and baking powder and mix together until you have a smooth batter.

Put your Oreos in a sturdy plastic bag and beat them into a rolling pin until they’re nicely crushed. You can also do this in a food processor if you feel like it. Fold in your Oreo crumbs, don’t be tempted to beat them in or mix them with your cake mixer, this makes the mixture a fairly uniform but unattractive dirty brown colour. If you fold them in, the colour and texture are much better!

Divide the mixture equally between the three tins. You can weigh them to make sure they’re fairly equal if you’d like. Bake in your pre-heated oven for around 20 mins until golden and they’re cooked. Remove from the tins and leave to cool on a cooling rack.

Leave your cakes to cool, preferably overnight before decorating them.

To make your frosting, scoop your vanilla frosting into a bowl and fold in your crushed Oreos. Again, if you beat them in the frosting will go a funny colour and texture, the less you play with this the better.

Your sponge layers may have a domed top, if you’re being a stickler for good looks, then you can carefully trim the top flat with a good knife. If this is for an occasion and not just for scoffing, I will trim the top layer, but turn it upside down, so the top of the cake is guaranteed to be perfectly flat.

Recipe: Oreo cookies and cream cake

I like a slightly rustic look to my cakes, so I used an offset palette knife to spread a generous slick of frosting between each layer and then cover the whole lot in the frosting. The cake was for a 12 year old, so the terrifying amount of sugar here wasn’t a problem, but if you wanted to cut down the sugar a bit, you could always just do an artistic swirl on the top. I decorated the cake with a few leftover (pah!) cookies and some crumbs. 

I made two of these cakes for his birthday. One was plain and simple, and the other one was turned into a Warhammer Purity Seal cake. Both cakes were a huge success and were gobbled down quickly by friends and family. Everyone loves Oreos, right?

If you enjoyed this recipe, you might also like to try this peanut butter Oreo ice cream.

Recipe: Oreo cookies and cream cake