To Make the Cake

1. Preheat the oven to 170c and grease two 20cm spring form cake tins. Line the bottoms with greaseproof paper.
2. In a small bowl, combine the psyllium husks with the water. Whisk well and leave to thicken.
3. Place a small, dry frying pan over medium/low heat and add the coriander seeds. Toast the coriander seeds for a few minutes, swirling the pan often, until fragrant. Do not allow the seeds to burn. Remove the seeds and transfer to a mortar and pestle or spice grinder. Grind roughly until coarse. Set aside.
4. In the bowl of a stand mixer fitted with the paddle attachment, combine the caster sugar and ¾ of the lemon zest. Beat for 30 seconds on medium speed until the sugar is fragrant with the lemon zest. If you don’t have a stand mixer, just rub the sugar and zest together with your fingers.
5. In a separate medium bowl, combine the flour, baking powder, salt and ¾ of the toasted coriander seeds. Set aside.
6. In the cup of a high speed blender, place the olive oil, soy milk, lemon juice, vanilla extract and thickened psyllium husks. Blend on high speed until smooth and thick (a few seconds should do it). If you don’t have a high speed blender, a hand blender or hand whisk should work too.
7. Add the blended olive oil mixture to the mixing bowl with the lemon sugar. If using a stand mixer, beat well with the paddle attachment until well combined. If making by hand, beat well with a silicone spatula.
8. Add the flour mixture and beat briefly until just combined. There should be no lumps of flour but make sure you don’t overwork the batter or the cake will be thick and dense.
9. Divide the batter between the two cake tins and place in the oven for 45 minutes or until golden brown and a skewer to the centre of the cake comes out clean.
10. Once baked, remove from the oven and place on a wire cooling rack.. Leave to cool for ten minutes before removing the cakes from their tins and allowing to cool fully.

To Make the Lemon Syrup

1. In a small saucepan, combine the icing sugar and the lemon juice. Mix well and place over low heat. Bring to a boil and reduce to a simmer. Allow to simmer for 3 minutes before removing from the heat.
2. Once the cakes are cooled, use a toothpick or bamboo skewer to make holes in the tops of each cake. Use a pastry brush to apply the lemon syrup to the cakes. Leave the cakes to absorb the syrup.

To Make the Lemon Buttercream

1. In the bowl of a stand mixer, fitted with the whisk attachment, place the vegan butter. Beat on high speed until fluffy (a few minutes). If you don’t have a stand mixer, use an electric hand whisk.
2. Working in four batches, add the icing sugar to the mixer, whisking well between additions.
3. Once the icing sugar is incorporated, add the lemon juice and extract. Whisk well until smooth and fluffy.

To Assemble

1. Transfer the buttercream to a piping bag with no nozzle. Pipe half of the buttercream between the two layers of sponge. Pipe a half of the remaining buttercream in a flat layer on the top of the cake and use the remaining half to decorate.
2. Sprinkle the remaining ground coriander seeds around the top edge of the cake and and decorate with the lemon zest. Slice and serve.