Fanny Mendelssohn Hensel's Sonata or Fantasia (originally written for cello and piano) arranged for bass clarinet and piano by Shannon Thompson. Thompson and pianist Lillian Buss Pearson premiered this arrangement in 2018 and performed it at ClarinetFest 2019 in Knoxville. You can listen to and download a recording of their performance of this work here.
 
This Digital Download is a pdf that includes the piano score, a part for bass clarinet to low C, and an alternate part for bass clarinet to low Eb.