Weekend fun is doubly sweet when it benefits those in need. Tomorrow’s Boston Pumpkin Festival at City Hall Plaza includes a free day (12 – 8pm) of family friendly entertainment, food, and pumpkins galore. Proceeds from the event will benefit Camp Sunshine, a national retreat for children with life-threatening illnesses and their families. And through Sunday nationwide, indulge in a cupcake at a participating bakery and mention Cupcakes for a Cause. Cupcake proceeds will benefit CancerCare for Kids. Locally, Rosie’s Bakery takes the cake as a major participant.