dash food colouring of your choice, optional
500g/1lb 2oz caster sugar
cornflour, for dusting
white fondant icing, to cover
400g/14oz icing sugar
500g/1lb 2oz self-raising flour, plus extra for dusting
3 tbsp vanilla extract
500g/1lb 2oz salted butter (at room temperature), plus extra for greasing
200g/7oz salted butter (at room temperature)
10 large free-range eggs
125g/4½oz good-quality raspberry jam