• 2 (450g total) unfilled sponge cake slabs (see note)
• 450g (3 cups) icing sugar mixture
• 50g butter, at room temperature
• 125ml (1/2 cup) hot water
• 4.40 gm vanilla extract
• 160ml (2/3 cup) thickened cream, whipped to firm peaks
• Hundreds and thousands, to decorate