To make the cake:
Lightly oil a loaf tin (5"x9") and line the bottom with non-stick baking paper.
Preheat the oven to 180°C
Sift the flour, baking powder and salt into a large mixing bowl and mix.
In a separate bowl mix together the sugar, agave syrup, oil, milk, vinegar and lemon juice.
Zest the lemon and stir in the lemon zest.
Add the wet ingredients to the dry ingredients and stir together.
Pour into the loaf tin and place on the middle shelf of the oven.
Bake until skewer inserted in the middle comes out clean (about 40 mins)
Once baked remove from the oven. Pierce all over with a cocktail stick (allowing the drizzle to pour inside). Spoon the drizzle evenly over the cake.
Allow the cake to cool for 30 mins before transferring to a cooling rack. Leave to cool completely before storing.
To make the Drizzle:
Squueze the juice of one lemon into a bowl (if you dont have a juicer twist a fork in the lemon whilst squeezing)
Stir with the sugar to combine