Beat together 250 grams of butter, 500 grams of Keto Baker London Baking Mix and 5 medium eggs until pale and creamy.
Then add the zest of 1 lemon and mix until well combined.
Line a loaf tin (8 x 21 cm) with greaseproof paper and butter (if you wish), then spoon in the mixture and level the top with a spoon.
Bake for 50-60 mins until a thin skewer inserted into the centre of the cake comes out clean.
While the cake is cooling in its tin, juice lemon to make the drizzle.
Prick the warm cake all over with a skewer or fork, then pour over the drizzle – the juice will sink in.
Leave in the tin until completely cool, then remove and serve. Will keep in an airtight container for 3-4 days, or freeze for up to 1 month.
Bon-appetite!