Author and cook Susie Fishbein seems to be building a devoted following. Her fifth cookbook, Passover by Design, sold 20,000 copies on the day of its release. Her Kosher by Design series has sold 250k over the years, and Fishbein has been making the rounds on talk and cooking shows. In Passover by Design, she helps the kosher cook by offering recipes without leavening so no additional substitutions would have to be made.