Preheat the oven to 190/170 fan/375/gas 5. Grease two sandwich tins, either 7” round, or 6” square.
Cream the butter and sugar together until light and fluffy. Add the vanilla essence and slowly stir in the beaten eggs, a little at a time.
Add the flour and baking powder to the mix, sifting as you go. Fold the flour in gently, if you over stir, the cake won’t rise well. You want the batter to be loose but not wet, add a little water if it is too dry (I added 2 tablespoons)
Once no dry ingredients are showing, divide the mixture between the two tins. Flatten the top of each, and bake for 20-25 minutes, until the top springs back when pressed and is golden brown.
Leave in the tin for about 10 minutes, as it cools the sides will shrink back from the pan making it easier to remove. Take out of the pan, and let cool on a cooling rack.
When cool, spread one cake generously with raspberry jam. Pop the other cake on top, and sprinkle that one with icing sugar (or whatever topping you want to use).