Preheat the oven to 180C/360F/Gas 4.
For the cake, grease two 23cm/9in spring-form cake tins and line with baking parchment.
Whisk the butter and the sugar in a bowl, using an electric whisk, until light and creamy for about five minutes(the mixture should be almost white in colour).
Add the eggs, one at a time, beating constantly until completely combined before adding the next egg. If the mixture starts to curdle you can rescue it by sprinkling in a tablespoon or so of the flour.
Add the vanilla extract and fold in the flour.
Divide the mixture between the two cake tins and place into the oven to bake for 25-30 minutes, or until completely cooked through. Test the cake is cooked by inserting a metal skewer into the centre of the cake. If it comes out clean the cake is cooked.
Remove from the oven and leave to cool for five minutes, then remove the cakes from the tins and leave to cool on a wire rack.
Meanwhile, for the butter cream, place the icing sugar, softened butter and hot water into a clean bowl. Mix well until completely combined and creamy.
Add the cinnamon and mix well.
To serve, trim the top off one of the cakes to make a level surface.
Spread the raspberry jam over the top of the levelled cake surface, then cover the jam with a layer of the butter cream.
Sandwich the second cake on the top and press down lightly.
Dust the top of the cake with icing sugar and serve in generous slices.
