This rich and creamy Yule log is not for the faint-hearted - it's a decadent triple-chocolate ... the buttercream icing, beat the butter until soft, then sift in the icing sugar and cocoa.
Set aside to cool. Put the cream into a large bowl with the cornflour and icing sugar and begin whipping. As soon as the mixture begins to thicken, pour in the chocolate hazelnut spread and keep ...