Complex sentence: Schama has a literary way of writing that is attractive not only to historians but non-historians and is "packed with evocative detail: rich fruit cakes crammed with raisins, currants, nuts and glacé cherries all mulled in brandy sauce".
Split into simpler sentences: Schama has a literary way of writing that is attractive to both historians and a wider readership. It is "packed with evocative detail: rich fruit cakes crammed with raisins, currants, nuts and glacé cherries all mulled in brandy sauce".