Grease and line the base of two 19cm/7.5ins loose bottomed cake tins.
Preheat the oven to 180 deg fan assisted.
Using an electric mixer. Beat together the butter and sugar until light and fluffy.
Gradually add the eggs, one at a time, adding a little flour between each one. This will help prevent curdling. Mix together until well combined.
Add the vanilla extract and the remaining flour. Mix until well combined.
Your batter should be of a dropping consistency. (drop off your spatular easily) If not, add the milk and mix until well combined.
Pour the cake batter evenly into the two cakes tins. Use scales to ensure you have an equal amount in each tin, or this will affect your baking times.
Bake in the centre of the oven for 20 mins. Or until baked. Testing the centre of each cake with a skewer until it comes out clean.
Leave in the tins for 5 - 10 mins to cool a little, before turning out onto a wire rack to cool completely.
Turn one of the cakes upside down to flatten the dome.
When cooled completely place the flattened domed cake on a cake stand with it's base facing upwards. Spread a layer of Raspberry or Strawberry jam. Place the second layer on top.
Dust with a light coating a caster sugar.
This cake will keep for a few days in an airtight container. But is best eaten on the day it's made.If you keep it in the fridge, the sponge will harden due to it being made with butter. Bring to room temperature before serving.