Vegan San Marcos cake

A 3-tier sponge cake soaked in rum syrup, with layers of vegan whipped cream and cocoa whipped cream, and topped with caramelised mango.


Hola!

Today I bring you a vegan version of my favourite birthday cake, called tarta de San Marcos. It’s a 3-tier luscious sponge cake soaked in rum syrup, with layers of vegan whipped cream and chocolate whipped cream. The sides are covered with roasted chopped almonds, and the top has mango pulp caramelised with a blowtorch like a crème brûlée.

This was a great challenge for me because I’m no expert in vegan baking, or generally in sponge cakes, so I had to upskill myself to make sure it turned out well. Even if you feel daunted by making the whole recipe, there are still very good tips to make a good vegan sponge cake. Have a read through!

PLANT POWER, MAKE UP!

My iaia used to buy me this cake for my birthday, because she knew I loved it (before I was vegan). This type of moist layered cakes is not that common in the UK. We see more often too sweet fruit cakes covered with a sugar blanket (icing). No flavour complexity and all looks before taste. No, thanks! I’ve been craving the San Marcos cake for a while, and no better occasion than my own birthday.

The sponge cake is relatively easy to veganise. I’ve learnt a few things that did make the difference:

  • Use self-raising flour. It gives much better results to me.
  • Make a vegan buttermilk with the soy milk and apple cider vinegar before mixing in any other ingredients.
  • Use a stand mixer or electric whisk to make the batter as airy as you can.
  • DO NOT open the oven until the first-time mark (unless you smell burnt lol). I know it’s tempting, but this is often the main cause for sponges to collapse.
  • If your sponge is slightly burnt on the edges, don’t throw it away. I used a grater to shave off the burnt bits, and like new! I was not going to make a new sponge cake from scratch.
  • The slicing of the sponge was nerve racking, and after realising that the cake took forever to bake because it was thick, and it burnt a bit, I would recommend to use 3 moulds to make the 3 layers, rather than making a big cake and slice it in 3 layers.

For the vegan whipped cream, I originally used use coconut milk, left overnight in the fridge and then collected the fat the next morning to whip it, with very inconsistent results. I hated it. Nowadays, I just buy chilled whipping coconut or oat cream, and the stand mixer does a fantastic hassle-free job.

And finally, for the vegan egg yolk on top, I used mango pulp. It comes in a can and the blend is so fine that it didn’t need any further processing. The consistency and colour were perfect, although the flavour is fruiter than egg yolk, but still amazingly good.

I split the work between two days, since the sponge is better to assemble when cool and the whipped cream needs to be very cold as well.


VEGAN SAN MARCOS CAKE (TARTA DE SAN MARCOS VEGANA)


Serves: 8-16 people
Prep: 2 days
Bake: 35 minutes


INGREDIENTS

Sponge
1 tbsp. cider vinegar
2 cups unsweetened soy milk
1 cup sunflower oil
2 and 1/2 tbsp. vanilla extract
3 and 1/4 cup self-raising flour
1 and 1/2 cup demerara sugar

Vegan whipped cream (plain and chocolate)
3x 250g chilled whippable oat or coconut cream
2/4 + 1/4 cup icing sugar
1 and 1/2 + 1 and 1/2 tsp. vanilla extract
4 tbsp. cocoa powder

Sugar syrup
1 cup water
1/2 cup demerara sugar
1 tbsp. lemon juice
1 tsp. almond essence
1/4 cup rum

Mango topping
1 can mango puree (850g)
1/4 cup cornflour, sieved
1 tsp. vanilla extract
Demerara sugar to caramelise

100g roasted chopped almonds


INSTRUCTIONS

  1. On day one, we’ll bake the sponges and make the whipped cream. For the sponge, mix the soy milk and the vinegar and leave aside for 5 minutes to make the buttermilk. Whisk the oil and the vanilla extract (manually or stand mixer). In a separate bowl, add the sugar and sieve the flour in. Mix the soy buttermilk in with the oil/vanilla while whisking, and start adding the flour/sugar while whisking continuously to incorporate well. You should get a smooth batter. Grease three sponge moulds (22cm diameter) and split the batter equally. Bake for 20-35 minutes in a preheated oven at 180°C or until fully baked. Let cool down for a couple of hours or overnight.
  2. While the cake bakes, make two batches of whipped cream in a stand mixer or with an electric whisk. First with two cream packs and the second with one. Sieve and slowly add the icing sugar, 2/4 cups for the two packs and 1/4 for the one pack batch, and split the vanilla extract for the two batches, adding it little by little. Keep whipping for about 5 minutes or until you make stiff peaks. Sieve and add the cocoa powder to the smaller batch, mix well and keep both in the fridge overnight.
  3. Next day, for the syrup, add the water and sugar, lemon juice and almond essence to a saucepan, bring to a boil, simmer and stir continuously until all the sugar is dissolved. Remove from the heat and mix in the rum. Let cool down.
  4. To make the mango topping, add all the ingredients to a saucepan (except the caster sugar), turn the heat to medium and stir continuously until it thickens. Remove from the heat and let cool slightly.
  5. It's assembling time! Prepare two piping bags: one for the chocolate cream and one for the plain whipped cream, the latter to be refilled. Level off the cakes with a knife. Put the first tier on a rotating cake stand, brush 1/3 of the syrup across the whole surface. Let it embed the sponge for a couple of minutes. Pipe on top a layer with all the chocolate cream and add the middle sponge tier. Repeat the syrup step and pipe the plain whipped cream. Add the last tier and repeat syrup step. With the third plain piping bag, cover the sides with the help of a spatula (there must be some left for the top edges). Stick the chopped almonds on the sides with your hands. Put the mango topping on top and use a spatula to make it flat. Keep it in the fridge until it sets. Sprinkle a good layer of demerara sugar on top and use a blowtorch to caramelise it (optional). Put the cake back in the fridge for 30 minutes. And finally, pipe the remaining whipped cream around the top edges. 

Bon profit!