YouTube's Edge of Seventeen is rounding out its cast.


The TV spinoff has enlisted comedy favorites Aya Cash (You're the Worst) and Lennon Parham (Playing House).


Based on the 2016 film from Robert Simonds' STX Entertainment, Annabel Oakes (Amazon's Transparent, Netflix's Atypical) will pen the script for the pilot, which revolves around Mira (Isabelle Fuhrman, taking on a version of the Hailee Steinfeld role), a high school student, and her best friend, Lou (short for Louise, played by Liana Liberato), as they navigate the relationships, feelings and realities of being teenage girls. Kelly Fremon Craig, who wrote, directed and produced the feature, is attached to executive produce the YouTube iteration.


Cash, currently starring on the final season of the FXX critical darling You're the Worst, will recur as Ms. Cosimano, a new teacher at the high school in which the potential series is based. Parham, currently appearing on ABC's Goldbergs spinoff Schooled, will recur as Bonnie, the mother to Mira.


Steinfeld, who earned a Golden Globe nomination, starred in the Edge of Seventeen feature as Nadine, a teen outcast balancing strained relationships with her overly dramatic mother (Kyra Sedgwick) and her popular older brother (Blake Jenner), who begins dating Nadine's best friend (Haley Lu Richardson). Woody Harrelson co-starred as a sympathizing high school teacher.


Oakes (Amazon's Transparent, Netflix's Atypical) will direct the pilot, which is being exec produced by Craig. Production is set to begin in January in Los Angeles.


Cash, who next appears in FX's Fosse/Verdon (set to bow April 9), is repped by UTA and Paul Hastings. Parham is with UTA, Rise Management and Morris Yorn.


Edge of Seventeen is one of a handful of scripted projects that remain in the works as YouTube plans to scale back on the genre beginning in 2020. The move arrives as the platform plans to focus on its free ad-supported business by making all future originals free to its 2 billion users, regardless of whether they pay a monthly subscription rate for YouTube Premium.