To make the sponge:
To make buttercream:
Grease two 180mm straight sided baking tins. Line the bottoms with buttered greaseproof paper.
Put the butter and sugar in a bowl. Using a hand mixer, beat at medium speed until fluffy (1-2 minutes).
Reduce speed. Gradually add the eggs, then the vanilla, then the flour. Increase to medium speed once the ingredients start to incorporate.
Put the mixture into the baking tins. Bake in a pre-heated oven at 180°C for 25 minutes. The surface should be golden brown.
Cool on a wire rack. Turn one sponge upside down. Put a layer of raspberry jam on top. Put the other sponge on top of the jam. You can replace the raspberry jam with other fillings, like buttercream.
Add flavourings a little at a time, and taste before adding any more.
Put the butter and sugar in a bowl. Beat at medium speed till fluffy (1-2 minutes).