Preheat the oven to 170°C/325°F/gas 3. Grease two 20cm sandwich tins and line the bases with greaseproof paper circles, then lightly dust with flour.
Beat the butter and sugar together until light and fluffy – you can do this by hand, or in a food processor.
One-by-one, beat in the eggs, then sift in the flour and fold through. Split the vanilla pod lengthways, then scrape out the seeds and add to the mixture.
Divide the mixture between the prepared tins and spread out evenly, then bake for 20 to 25 minutes, or until golden, risen and an inserted skewer comes out clean.
Leave to cool slightly in the tins, then transfer to a wire rack to cool completely.
Finely grate the lemon zest into a bowl, add the icing sugar and cream, then whisk to soft peaks.
To assemble, spread an even layer of jam over one of the cakes, followed by a layer of the lemon cream, then dot the raspberries over the top. Sandwich the second cake on top, dust with icing sugar, then serve.