Pre-heat the oven to 180°C fan and line a 2lb loaf tin with baking paper or a loaf tin liner.
Pour the unsweetened almond milk into a jug, add the apple cider vinegar, stir and set to one-side for 10 minutes until the mixture curdles.
To make the flax eggs, add the milled flaxseed to a bowl with 6 tablespoons of water, stir and leave until it thickens.
Tip the pistachios into the small bowl of a food processor and blend until they become a fine flour.
Remove the seeds from the cardamom pods and use a pestle and mortar to grind them into a fine powder.
Add the ground almonds and ground pistachios to a large mixing bowl, sift in the plain flour, add the baking powder, bicarbonate of soda and stir.
Add the sugar, clementine/orange zest, ground cardamom and stir together.
Make a well in the centre of the dried ingredients and add the olive oil, almond milk with apple cider vinegar and the flax eggs. Stir to combine until you have a smooth cake batter.
Spoon the batter into a lined loaf tin and place on the middle shelf of the oven. Cook for 40 minutes, until golden on top and the sponge springs back when touched.
Whilst the cake is in the oven make the clementine drizzle by adding the icing sugar to a small saucepan pouring in the clementine/orange juice. Gently heat until the icing sugar has dissolved into the clementine juice.
Remove the cake from the oven and place on a wire cooling rack. Keep the cake in the tin.
Prick the warm cake all over with a cocktail stick and drizzle over the clementine mix. Scatter the top of the cake with 20g of roughly chopped pistachios. Leave the cake in the tin to cool fully before removing and slicing.
Keep in an airtight container and eat within 3 days.