Producers: Jeremy Garelick, Mickey Liddell, Pete Shilaimon, Will Phelps, Glen Trotiner and Sam Slater   Director: Benjamin Kasulke   Screenplay: Hannah Marks and Joey Power   Cast: Hannah Marks, Liana Liberato, Dylan Sprouse, Luke Spencer Roberts, Addison Riecke, Jessica Hecht, Jacob Batalon, Haley Ramm, Megan Kimberly Smith, Travis Przybylski and Ben Konigsberg   Distributor: Vertical Entertainment

Grade: B-

A high school rom-com that’s better than most but still rather undernourished, “Banana Split” was co-written by actress Hannah Marks.  She also stars as April, whose romantic relationship with Nick (Dylan Sprouse) over the course of their senior year is sketched in an opening montage (one of too many), which begins in their becoming an item and ends in their breakup as they get college-acceptance letters.

April’s miserable over the turn of events, but Nick considerably less so: he quickly moves on with Clara (Liana Liberato).  Trying to make April feel better is Ben (Luke Spencer Roberts), the inevitable goofy guy with the funny hat who happens to be best buds with both her and her now-ex.  He accompanies April to a party where they unexpectedly encounter Nick and Clara.  April is initially frosty, but Clara approaches her with a friendly air, and without much ado they bridge the gap between them and become buddies themselves—being careful to keep their relationship from Nick, and agreeing not to talk about him.

Over the course of the summer the girls’ friendship deepens substantially, turning into a virtual romance.  There’s a wrinkle when Ben finds out about them, and wrestles with whether he should—or can, given his tendency to blurt things out—keep the truth from Nick as they talk over things during their breaks at work.  But the girls manage for most of the summer, even when the secret is endangered (they even adopt aliases—Brad Pitt and George Clooney—for their texts to one another).  Only as everyone starts preparing to depart for their various colleges do serious obstacles arise, mostly from April’s increasing irritation over Clara’s continuing relationship with the oblivious Nick.

There’s obviously a schematic quality to this narrative, and the addition of the hapless buddy to the mix—Roberts, who scrunches up his face entirely too much to show his discomfort, is like a teen version of the characters that used to be played by Gig Young or Tony Randall in Doris Day-Rock Hudson comedies—doesn’t help.

But “Banana Split” is made more digestible by a few factors.  One is its female empowerment emphasis, even though there’s still a pronounced element about girls identifying themselves by their relationship—or their attractiveness—to a man.  Certainly the main male character, Nick, is a pretty bland sort compared to April and Clara, though Dylan Sprouse plays him nicely enough; he emerges not as a bad sort, but basically as a pleasant but rather empty-headed guy.  You know the type.  Jacob Batalon, of the Tom Holland “Spider-Man” movies, appears briefly as April’s boss as the theatre where she works, a guy whose come-ons to her are a mite creepy rather than funny.

By contrast the two female leads have greater opportunity to shine.  That’s true not only of Marks, who—as one of the writers—has given April lots of energy and amusing lines (as well as a dramatic arc, even if it’s pretty obvious), but of Liberato, who invests Clara with intelligence as well as empathy.  The two work well together.  Unfortunately, there’s a hiccup on the distaff side in the subplot regarding April’s home life.  Her mother (Jessica Hecht) is standard-issue concerned but clueless, while her younger sister (Addison Riecke) is one of those irritating kids determined, for reasons that will be revealed, to make her older sibling’s life miserable and does the same for ours.

Helming his first feature, cinematographer Benjamin Kasulke does a reasonably good job, creating an authentic high school atmosphere while drawing mostly strong performances from his cast, even if his leads are older than the milieu demands.  He and editor Brendan Walsh keep things moving at a sprightly pace, though their use of montage as a shorthand can be annoying, while production designer Almitra Corey and cinematographer Darin Moran add nicely to the atmosphere.  Annie Hart’s choice of music adds to the mood.

For as long as it lasts, “Banana Split” is a reasonably tasty confection, but in the end its nutritional value is low.