Preheat the oven at 180?C and prepare you cake pans. This recipe makes two 9-inch cakes.
Combine the flour, baking powder and salt.
Beat the butter with the sugar until light and airy for about 3 minutes and add the eggs one by one beating in between to incorporate. At this point add the vanilla essence.
Add 1/3 of the flour mixture, mix and add 1/3 of the milk. Continue the same way by alternating flour and milk till it is all incorporated.
Pour the mixture in the cake pans and bake for about 30-35 min.
For the raspberry filling and buttercream
Chop the raspberries in small pieces add the sugar and the lime juice and stir.
Once the cakes have cooled down spread the mixture on their bottom side to soak.
Now you can prepare the buttercream. Beat the butter until it becomes smooth and add half of the raspberry purée.
Keep mixing and add gradually the icing sugar and the rest of the raspberry purée. At the end add the double cream. Keep in mind that you might need to add some more of the double cream if your icing is runny. You can also make it sweeter by adding more sugar.
Place the cakes one on top of the other, and ice with the buttercream. For a professional looking icing put a thin coat on the cake first and let it set in the fridge for 30 min or so. Then you can add the rest of the icing and it will look smooth and perfect!