Once, an “alternative chocolate cake” was something we made for Passover, usually from a Manischewitz mix. As much as my Mom and I tried, no cake recipe calling for a matzo derivative ever produced anything remotely fluffy or moist. (I swear Manischewitz cheated.) Sometime in the 1960s, French-inspired bakers adventured with eggs, nuts, butter, and intense flavorings to create decadent chocolate cakes with minimal flour. So a kind of Fifth Question inevitably swept the Passover baking community. “On all other nights we can eat flourless cake. On this night, why can’t we eat matzoless cake?” Zell Schulman helped lead the Exodus into the land of glorious desserts with this recipe for Chocolate Mousse Torte…