While the chocolate snack cake layers are cooling, it’s time to whip up the creamy vanilla filling. Make sure your butter is softened but not melted—melted butter will make the filling too runny.

To make the filling, gently melt the white chocolate in a heatproof bowl sat ... Press the biscuit mixture into a 20cm/8in springform cake tin, letting some come a little way up the sides.

Grease the base of a 20cm/8in springform cake ... filling, suspend a heatproof bowl over a pan of gently simmering water (do not allow the base of the bowl to touch the water). Add the white ...