• Preheat oven to 180c.
• Grease and line a 21 x 11 x 6cm (8½ x 4½ x 2½") loaf pan with baking/parchment paper and set aside.
• In a medium bowl, mix together melted butter and caster sugar.
  75 g salted butter, 280 g caster sugar
• Then add sour cream, eggs, vegetable oil, lemon juice, lemon zest and essences then mix to combine (it will look curdled but that's ok) then set aside.
  240 g sour cream, 2 eggs, 4 tablespoon vegetable oil, 3 tablespoon fresh lemon juice, 2 tablespoon grated lemon zest, 1½ teaspoon lemon extract, 1 teaspoon vanilla extract
• In a large (separate) bowl add flour and baking powder and whisk to combine.
  300 g plain flour (all-purpose flour), 1 tablespoon baking powder
• Add the wet ingredients to the dry ingredients, folding gently until just combined (don't overmix).
• Pour the batter into the prepared tin and bake (uncovered) for 40 minutes. Then cover loosely with aluminium foil and bake for a further another 20 - 25 minutes until a toothpick/skewer inserted in the centre of the cake comes out clean with no raw batter.
• Allow to cool completely before glazing.

For the glaze

• In a small bowl combine the icing sugar and lemon juice (starting with 2 teaspoons), adding more juice ½ teaspoon at a time until you get the right consistency (see my notes).
  150 g icing sugar (confectioner's sugar/superfine sugar), 2 - 4 teaspoon fresh lemon juice
• Spread the glaze over the cooled cake then slice and serve.