Courgette Cake (Zucchini Cake) with Brown “Butter” Frosting

zucchini cake or courgette cake

An insanely moist and flavoursome Courgette Cake (Zucchini Cake) with a hint of lemon and a perfectly even crumb! The subtle flavour of the cake allows the vegan brown “butter” frosting to take centre stage, with its irresistible nutty, malty flavour.


For the Cake
  • 3 t ground psyllium husks (or 3 T ground flax seeds)
  • 10 t water (or 9 T of water if using flax)
  • 325g courgettes/ zucchinis (around two small courgettes/ zucchini)
  • 365 g plain flour
  • 1.5 t baking powder
  • 1 t baking soda
  • ½ t salt
  • 200 ml unsweetened plant milk
  • 1 t lemon juice or cider vinegar
  • 1 t vanilla
  • 250 ml vegetable oil
  • 320 g caster sugar
  • 2 T lemon zest
For the Frosting
  • 250g icing sugar
  • 110g vegan butter (room temperature - see note below)
  • 1 t vanilla extract (optional)
  • 4 T toasted hazelnuts


To Make the Cake

  1. Preheat the oven to 180c/355f fan. Grease and line a 32x24cm sheet pan or roasting tray.
  2. In a small bowl whisk together the ground psyllium husks/ground flax seeds with the water. Set aside to thicken into your “egg” mixture.
  3. Using a box grater, grate the courgettes/ zucchini into a medium bowl then transfer to a nut milk bag or piece of muslin/cheesecloth. Over the bowl, squeeze out as much moisture as you can from the courgettes/ zucchinis. You can reserve the liquid to use in smoothies and juices if you like. Set aside the grated, drained courgettes/ zucchinis.
  4. In a medium bowl mix together, the flour, baking powder, baking soda, and salt. Set aside.
  5. In the cup of a high-speed blender or food processor, add the plant milk, lemon juice, vanilla, vegetable oil, and thickened psyllium husks. Blend on high speed for 30 seconds. If you don’t have a food processor, use an immersion blender. The blended mixture should be thick, smooth, and creamy, almost like mayo. Set aside.
  6. In a large bowl or the bowl of a stand mixer fitted with the paddle attachment, place the caster sugar and lemon zest. Add the plant milk/vegetable oil mixture and beat well until the mixture is smooth and glossy.
  7. Add the flour mixture in three additions, mixing gently between each addition. Do not over-work the batter. Finally, add the grated courgettes/ zucchini and mix to combine. Pour the batter into the prepared tin and place in the preheated oven. Bake for 40 minutes, rotating the sheet-tin halfway through.
  8. Once baked, remove from the oven and place the baking tray on a wire cooling rack. Allow the cake to cool completely.

To Make the Frosting

  1. Once the cake is room temperature, sieve the icing sugar into a medium bowl and set aside.
  2. If using a vegan butter which browns (see note below) place half of the vegan butter (55g) into a medium saucepan and place over medium heat. Allow melting, stirring constantly, until it foams. The foam should subside and the vegan butter will begin to be dotted with small dark flecks. Don’t allow the butter to burn, just brown. Remove from the heat and pour it into a medium bowl. Allow cooling for 10 minutes.
  3. If you don’t have access to vegan butter which browns, add a tsp of vanilla extract at this stage.
  4. Once the browned butter is cooled slightly pour it into a large bowl or the bowl of a stand mixer fitted with the whisk attachment. Add the other half of the vegan butter and whisk together until completely smooth.
  5. Add the icing sugar in four additions, whisking well to ensure the frosting is smooth. Once all the icing sugar is added, frost the now completely cooled cake. Once frosted, top with a few toasted hazelnuts, just to add some more nuttiness to the cake.
  6. Slice the cake into pieces and serve.


This is a super easy cake, but here are a few tips on getting an absolutely perfect bake!

Start with the Psyllium Husks/Flax Seeds

These guys will act as your egg replacement and will help hold the whole batter together. Whether you’re using psyllium husks or flax seeds, you’ll need to grind them into a rough powder (you can do this in a blender or spice grinder) and mix them with water to hydrate. Set aside to thicken.

Wet Ingredients

This recipe works best when your wet ingredients are completely emulsified. This is why it’s best to use a blender for this stage. The mixture will thicken, almost like mayonnaise, when you blend it – this is good! It’ll mean a super smooth, even crumb. Oh and don’t forget to add your thickened psyllium husks – these guys are essential!

Drain The Courgettes (Zucchinis)

The courgettes (zucchinis) in this recipe add a lot of moisture to the cake, which is a good thing! However, if you don’t drain them before adding to the cake batter, you’ll end up with way too much moisture in the cake. This will create a dense, rubbery crumb, which definitely is not a good thing. Once your courgettes are grated, throw them in a nut milk bag or some muslin and squeeze out the excess moisture. You can reserve the courgette “juice” for in smoothies or juices!

Combine with the Sugar

Now we mix together our super-smooth wet ingredients with our sugar. It’s good to add the lemon zest at this stage because all the essential oils become absorbed by the sugar, boosting their flavour.

Add the Dry Ingredients and Courgettes (Zucchinis)

Now you have a smooth batter, you need to add in the dry ingredients and the courgettes (zucchinis). Try to avoid overmixing the batter at this stage. You’ll activate the gluten and end up with a dense cake.

Bake and Cool

Bake the cake in a rectangular cake tin for 40 minutes until lightly golden on top. Before frosting, make sure you allow the cake to cool completely to room temperature.

Make the Frosting

This frosting relies upon “brown butter” for flavour. Not all vegan butters have the ability to “brown” which is the process whereby the butter is heated and its solids are caramelised, giving it a beautifully nutty flavour. In the UK and Europe, try to use the Naturli brand. In the US use Miyokos. Both of these brands will brown just like dairy butter. If you can’t access butter which browns, just use what you have, but add an extra tsp of vanilla for flavour!

Frost, Slice and Serve

Frost the cake and top with the hazelnuts if desired! Slice into around 15-20 slices. Serve and enjoy!

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