Vegan kumquat layered cake
This vegan kumquat layered cake is sandwiched with layers of fluffy vanilla buttercream and garnished with dried kumquat slices! It’s light, super flavorful, and sure to impress.
I spotted some fresh kumquats at my local fruit and vegetable market last week and immediately knew I wanted to use them to decorate a cake! I had this vision of a layered cake with kumquat slices travelling up the side, almost like a fault line cake. So I started brainstorming what flavours to use and soon this vanilla cake with homemade kumquat marmalade and kumquat crisps was born! It’s honestly one of my favourite cakes I’ve ever made!
Tips for the vegan kumquat layered cake
Make the dried kumquat slices the night before if you can: If you want to save time you can prepare the kumquat crisps the night before and use them to decorate the cake the next day. Otherwise, start in the morning and let them dry for 3-4 hours.
Don’t freeze your kumquats for too long: I usually freeze the kumquats for half an hour before slicing with a mandoline or a sharp knife.
Rest your cake batter: I do like resting my cake batter for 2-3 hours as this allows the gluten to relax and the flavours to melt together.
Ingredients for the kumquat cake
Kumquats: Kumquat is a wonderful fruit which is very similar to oranges but without the bitterness of the white flesh that oranges have. You can cut the kumquat as fine or as chunky as you like depending on the consistency you prefer for your marmalade.
Emptied vanilla pods: Never throw away your vanilla pods after you scoop out the caviar as the vanilla pods are perfect for flavouring any jams, syrups etc.
Vanilla soya yoghurt: I love soya yoghurt in vegan baking as it makes sponges so light and fluffy. I tend to use vanilla yoghurt as it is already sweetened and flavoured with vanilla. If you want to use plain soya yoghurt, you can add 20g of sugar to the batter.
Apple cider vinegar: When combined with yoghurt, apple cider vinegar makes the sponge tender and fluffy.
Vegetable oil: I tend to use vegetable or rapeseed oil for most of my cake batters but you can use any neutral oil.
Cake flour: Cake flour is not the same as all-purpose flour, as cake flour has cornstarch added to it. You can make your own cake flour by sieving together 300g all-purpose flour with 60g of cornstarch.
Vegan butter: Vegan butter has a very similar texture to dairy butter resulting in a very flavourful buttercream. I love flora vegan butter( not sponsored just genuinely a fan)!
Trex: Trex is another favourite vegan alternative. While Trex doesn’t add much flavour, it offers stability and creaminess to the buttercream.
Icing sugar: I cannot stress enough how important it is to always sieve your icing sugar, especially for frostings and buttercreams. It is the only way to ensure your buttercream is smooth and creamy.
Soya milk: I like using a small amount of vegan milk to thin out my buttercream and make it slightly more pliable. I like using soya milk as it is neutral compared to other vegan kinds of milk.
For the kumquat crisps
- 8 firm kumquats
- 100g water
- 100g sugar
- 1 emptied vanilla pod(optional)
For the kumquat marmalade
- 230g prepared kumquats
- Zest and juice of 1 lemon
- 120g water
- 120g caster sugar
- 1 vanilla pod emptied
For the vanilla sponge
- 500g vanilla soya yoghurt(or plain)
- 2tsp apple cider vinegar
- 1tsp vanilla extract or essence
- 160g vegetable oil(or any neutral oil)
- 280g caster sugar
- 360g cake flour
- 1tsp baking soda
- 1.5tsp baking powder
- 1tsp salt
For the vanilla buttercream
- 150g vegan butter
- 130g trex
- 35g soya milk(or any vegan milk)
- 1/2 tsp salt
- 560g icing sugar
- 1 tbsp vanilla extract
How to make the kumquat crisps
- Freeze the kumquats for 30-45 minutes or until frozen but not too hard. This way they will keep their shape while slicing.
- While the kumquats are in the freezer, place the sugar, water and emptied vanilla pods(if using) in a pan over medium heat and bring to the boil. Take off the heat and let the syrup cool completely.
- Preheat the oven to 110°C and line a baking sheet with parchment paper.
- Using a mandoline(*see Notes) or sharp knife, slice the oranges thinly but not too thin.
- Deep the kumquats in the syrup, so that they are covered in the syrup and place on the tray.
- Bake the kumquat slices for 2-3 hours or until they are completely dry (make sure to check on them frequently towards the end so they don’t burn).
How to make the kumquat marmalade
- Quarter kumquats lengthwise; cut off the white centre membrane and remove seeds. Slice quarters into small or larger pieces depending on how chunky you prefer your marmalade.
- Place kumquats into a pot. Add lemon zest (white part only), lemon juice, emptied vanilla pod, sugar and water. Mix together. Cover and let sit at room temperature 2 or 3 hours to allow fruit to macerate.
- Place pot over medium-high heat and bring mixture to a simmer, stirring occasionally. Reduce heat to medium; cook and stir occasionally for 5-7 minutes. Continuing cooking and stirring often until mixture is thick enough so that if you scrape a spatula across the bottom of the pan, you can briefly see the bottom of the pan before marmalade spreads back out 30 to 40 minutes. Remove from heat and allow to cool slightly 5 to 10 minutes.
- Transfer the marmalade into a sterilised jar. Cover and let cool to room temperature. Refrigerate until thoroughly chilled.
How to make the vanilla sponge
- Combine the vanilla soya yoghurt or plain soya yoghurt (*see Notes) with apple cider vinegar and set aside.
- In a bowl place cake flour(see Notes for substitute*), salt, baking soda, baking powder whisk until combined and set aside.
- In a separate bowl place sugar and vegetable oil and whisk until thoroughly combined.
- Add the yoghurt and vinegar mix and whisk until everything is just combined. Lastly, add the dry ingredients and whisk until there are no visible lumps of flour left.
- Place in an airtight container and refrigerate for 2-3 hours if you can.
- Preheat the oven to 160°C/fan.
- Spray 3 6×4 inch round cake pan and line with parchment paper.
- Weight around 410g of batter per tin and use a cranked palette knife to flatten.
- Bake for 30-35 minutes or until a toothpick comes out clean when inserted in the middle.
- Let the cakes cool for 10 minutes and invert onto a cooling rack to allow them to cool completely.
How to make the buttercream
- Place the vegan milk and salt in a small heatproof bowl and heat in the microwave for 20 seconds.
- In a large bowl using a handheld or stand mixer fitted with a paddle attachment, cream vegan butter and trex until light and fluffy.
- Add the icing sugar and beat the frosting on high for 4-5 minutes until light and fluffy.
- Add in milk and salt until fully combined.
How to assemble the cake
- Cut the tops of the cakes using a serrated knife to make them flat. Place the bottom layer of cake on an 8-inch cake board(2 inches bigger than your sponge) and place the board on your rotating cake. Spread about 1/4 of the buttercream evenly on top. Spoon 1/3 of the kumquat marmalade in the middle. Place the next layer on top and repeat. Place the final cake layer upside down so that the top of your cake is as even as possible. Using a flat palette cover the cake with buttercream on the top and sides catching any crumbs.
- Refrigerate your cake for 1 hour before applying the last layer for buttercream.
- Spread the last bit of buttercream using a palette knife, trying to make it as smooth as possible. Make sure to watch my Youtube video for full instructions on how to achieve a smooth cake.
- Attach the kumquat slices diagonally to the side of the cake.
- Refrigerate your cake for 2-3 hours before slicing.
- The cake is best enjoyed the same day, but you can slice the cake and store in an airtight container for up to 3 days.
- Enjoy 🙂
- If you want to use plain soya yoghurt you can add 20g of extra sugar as the plain version is unsweetened.
- If you don’t have cake flour you can simply sieve together 300g of all-purpose flour with 60g cornstarch.