Preheat the oven to 200 C / Gas 6. Grease and line a 20cm (8 in) with baking parchment.
Into the base of the prepared cake tin add two tablespoons of the butter and the light brown sugar. Place in the oven to melt.
In a mixing bowl, beat together the remaining butter and the golden caster sugar until fluffy. Add the eggs, lemon zest and vanilla extract and beat well until creamy.
In a mixing bowl, combine the flour, baking powder and salt and mix well.
Gradually beat together the wet and dry ingredients, slowly adding the milk until well combined.
Remove the cake tin from the oven and add the apricots, cut side up into the base. Pour the cake mixture over the apricots.
Bake in the preheated oven for 45 to 50 minutes, or until a skewer inserted into the centre comes out clean. Remove from the oven and allow to cool for 15 minutes.
To serve, place a serving plate over the top of the cake then flip upside down. Use the baking parchment to help you gently ease the cake out of the tin, then carefully peel away the paper leaving a lovely upside down apricot top to the cake. Slice and enjoy.
Sometimes ingredients may be processed in a facility that also processes nuts. Double check that your ingredients are all safe if catering for someone with nut allergies.