Pumpkin is a member of the squash family and in Turkish cuisine, squash soups are quite common. Balkabağı çorbası translates as 'honey squash soup' so you need a sweeter type of pumpkin. Depending on where you live, these are sometimes called sugar pumpkins. Kabocha squash whose taste resembles a mix of pumpkin and sweet potato is also a good choice. As is butternut squash.