I think this is my favourite sponge cake at the moment. My dad has an allotment so I like to use his raspberries when they're in season but when they're not in season I tend to buy frozen ones as they're usually cheaper and you won't end up wasting them.
The batter is a simple sponge cake mix:
8oz SR flour
8oz caster sugar
8oz softened butter
1 tsp vanilla extract
1 tbsp milk
1 tsp baking powder
Mix the sugar, flour, baking powder and butter and once combined add the eggs one at a time, along with the vanilla extract. Add the milk at the end.
Lay the raspberries (about 200g) on the bottom of two a pre-lined and greased tins, I don't tend to weigh out the raspberries but make sure they're neither touching nor sparsely spread.
Cover with equal amounts of batter.
Bake in a preheated oven at GM6 for approximately 40 minutes. You'll need to check the mix after about 30 minutes or so as the moisture from the berries can make the baking time a little unpredictable. The standard way of checking is to insert a skewer (or something small and narrow) into the middle of the cake, when it comes out clean, it's ready.
Once cooled, you can either fill it with whipped double cream, or use a cream cheese frosting which will keep for a couple of days.
For the cream cheese frosting:
Whisk 300g Philadelphia cream cheese until soft, add in 150g sifted icing sugar then 300ml double cream. Whisk together until 'stiff'.
This should be enough to cover the top and middle of the cake, if you wanted to cover the whole cake the recipe should be doubled.