When a PP is attached to the preceding NP or PP (henceforth referred to as noun attachment), such as in the structure ... eats pizza with anchovies, a phrase boundary between pizza and with is usually considered inappropriate.
when a PP is attached to the verb in the clause (verb attachment), as in the structure ... eats pizza with a fork, an intervening phrase boundary between the PP and its preceding NP or PP (between pizza and with) is optional, and when placed, usually judged appropriate (Marsi et al., 1997).