Born in Modena, Italy, Piancastelli moved to Carlsbad, California with her family at age five and graduated from Carlsbad High School in 2014. She attended McNeese State University in Lake Charles, Louisiana. With the McNeese State Cowgirls softball team, she debuted on February 6, 2015 in a win against Florida Gulf Coast, with a 2/4 performance with a double and a RBI. She would earn conference Freshman and Player of The Year accolades and was recognized Third Team All-American by the National Fastpitch Coaches Association after leading the team in hits, average, RBIs, home runs, doubles and slugging, the homers were a new school record and her hits and average career bests. On March 6, Piancastelli hit two home runs to drive in a career-best 5 RBIs against the Sam Houston State Bearkats. In her sophomore campaign, Piancastelli earned her second conference and NFCA honors. She broke the school records for home runs, slugging and walks, all career highs, the latter stat also set the conference standard. Beginning on March 3–18, the cowgirl went on an 11-consecutive-game hit streak batting:.469 with 18 RBIs, 6 home runs, four doubles, 6 walks and slugging 1.687%. Later, she would set a single game McNeese record with 5 walks on April 16, in a defeat of the Northwestern State Demons. She would achieve a second single-game highlight for hits with a perfect day at the plate on May 13 against the Lamar Cardinals, with a 4/4 performance. As a junior, she earned her third Player of The Year for the Southland and set a career best with 26 stolen bases. Piancastelli joined an elite club by collecting her 50th career home run in only her third year on April 21 vs. the Lamar Cardinals, striking off pitcher Amie Cisneros for an eventual victory. For a final year, Piancastelli was awarded her fourth and last Player of The Year honor. She set her last records with career-best RBIs and doubles. On April 27, Piancastelli tallied her 200th career RBI in a 5–0 win over the Stephen F. Austin Lumberjacks, hitting a solo home run in the first inning. Piancastelli currently owns nearly all offensive career records for the Cowgirls and is merely tied in average. She is the Southland leader in RBIs, home runs, doubles, slugging and walks. In all of the NCAA, she ranks 6th in walks and 7th in slugging for her career.
