Authorities say 59-year-old William Hotz tried to use an expired coupon at a Carvel store in Valley Stream around 11:30 a.m.
When he was told he couldn't, investigators say he stole the cone and left the store.
When the 55-year-old female clerk confronted him outside, Hotz allegedly punched her several times in the face, causing her to sustain a laceration and swelling to her lip.
Police say that Hotz refused to be handcuffed, flailed his arms and twisted his body when officers tried to take him into custody.
The victim declined medical treatment for her injuries.
Hotz is charged with third-degree robbery and resisting arrest.