Spicy Chocolate Rum Cake

gardnermmoore
May 18, 2020
4 min read

Updated: May 15, 2021

This is the 2020 quarantine iteration of the chocolate rum birthday cake I try to make for my friend every year. This is not a cake for children.

This recipe has been adapted from the Mexican Hot Chocolate Cake on the Preppy Kitchen blog (original found here: https://preppykitchen.com/mexican-hot-chocolate-cake/), and woah boy is it a revelation. A three layer spicy chocolate cake with browned butter chocolate rum infused icing. It takes about 24 hours from start to finish, so pull up your socks folks, pace yourselves, and remember, this is a marathon not a sprint.

Ingredients:

Cake:

3 cups/360g plain flour

2 2/3 cups/530g granulated sugar

1/2 cup/50g cocoa powder

1 1/2 tsp baking powder

1 Tbsp baking soda

1/2 tsp cayenne pepper

1/2 tsp ground cinnamon

1/4 tsp salt

1/2 cup/115g sour cream

1 cup/245g buttermilk

Or the wateriest plain yogurt you can find

3 large eggs

1 1/2 cups/340g cold strong coffee

3/4 cups/165g vegetable oil

1 Tbsp vanilla extract

Icing:

1.25lbs/575g unsalted butter

1 tsp cayenne pepper

1/4 tsp salt

2 1/2 tsp cinnamon

3/4 cup/75g cocoa powder

3-4 Tbsp dark rum

c. 4 1/2 cups/560g icing sugar (confectioner's sugar)

1/3 cup/100g chocolate ganache

This was supposed to be fudge, but USA fudge, the likes of which cannot be found in the UK

1/2 cup/90g semi-sweet or plain chocolate melted and cooled

Chocolate Rum Ganache

1 cup/200g semi sweet or plain chocolate chips, or chocolate chopped finely

1/2 cup/110g heavy cream, UK double cream

1 Tbsp dark rum

Instructions:

Prep Work:

Two things you have to do in advance of baking this cake are to make the ganache and the brown butter. These can be done any time between 12 and 30 hours before you start baking the cake. Sure, this is a bit of an assache, but it doesn't take too long, and the flavour of the rum ganache will be stronger with more time to set.

Ganache:

Set up a double boiler by placing a heatproof bowl above a pan of simmering water on low to medium heat

In the double boiler, scald the cream until small bubbles are forming around the edges

It will start to smell like custard. You will also smell if it is burned. The second picture shows what the cream will look like when it is done.

Add the chocolate chunks to the scalded cream, and add the rum

Ideally, do this by pouring the cream over the chocolate, but if not it will not be the end of the world, or the end of the ganache.

Let sit for a few minutes, and then whisk until smooth

Cover the ganache and leave to set at room temperature

Brown Butter:

Melt the 1.25lbs/575g butter for the icing in a medium saucepan on medium-low heat

Let it melt, and melt, and foam, and foam, and bubble, and bubble, and brown, and brown

All these stages are normal, let it keep on bubbling

You will know it is done when the milk solids have separated and there is an aroma of toasted nuts

Like so, the butter is finished browning when the caramelised milk solids are easily visible:

Allow the browned butter to cool and re-solidify, you will use it to make icing

You can see the separated and browned milk solids, and that the butter is darker in colour

It will take about 8 hours for the butter to re-solidify if left at room temperature. You can put it in the refrigerator to speed the process up, but make sure it is at room temperature before making the icing.

The first set of prep work is finished. Get some rest, rehydrate and brace yourself to return tomorrow for the business of fabrication and construction.

Coffee

Make an extra cup and a half of coffee in the morning and let it cool

Instant coffee is fine, but good strong filter coffee is ideal. This will take a few hours to cool to room temperature. If you need to, you can stick it straight in the refrigerator as soon as it's poured to speed up the cooling process.

Cake:

Preheat the oven to 350˚F/180˚C and set a rack in the middle of the oven

In a large bowl, sift together the dry ingredients, including the spices, and whisk to combine

In another bowl, whisk together the wet ingredients

Add the wet ingredients to the dry and whisk to combine

On a medium low speed, or by hand, beat for another 2 minutes

If you're weighing the dry ingredients, you can balance your sifting apparatus on the scale and just pour everything in there.

Prepare the pans by greasing and flouring them

This is a bit of a faff, but if you've got pan liners, USE THEM. I used three 8" pans for this, but you could probably make two 10" cakes or some tasty cupcakes (I have no idea how many)

1. Butter the pan

2. Press in the liner - if it is a little bit bigger than the pan that's ok, mine were

3. Re-butter over the liner

4. Knock around 1-2 Tbsp flour to coat the pan

Pour an equal amount of batter into each pan, and bake for 35-40 minutes until a toothpick inserted into the cake comes out clean

For me this was c.650g per pan.

Let cool in the pan on a cooling rack c.15 minutes before turning out

Invert cake onto a cooling rack, and very carefully remove the cake liner from the bottom

Allow to cool completely before icing

Icing:

In a large bowl, combine the browned butter, spices, salt, cocoa powder and rum

Beat with a paddle attachment of an electric mixer, or by hand

Slowly sift in the icing sugar and mix

Beat in the ganache/fudge and the melted chocolate

Beat until fluffy and well combined

It will be very hard not to eat so much of this you feel terrible

Assembly:

To assemble this cake, place the cake board or plate you plan to use on a turntable and smear a little bit of icing onto it in a thin layer to help the cake stick to the board

Put the first layer onto the board, centre it and spread a layer of icing over the top

Place the second layer on top of the first, and spread a layer of icing over the top

Place the third layer on top, and spread a layer of icing over the top and sides of the cake

(I did not need to crumb coat this one, but you most certainly could)