For the pastry, combine the flour, sugar, and lemon zest in a mixing bowl or in the bowl of a food processor. Cut or process in the salted butter with short pulses until the mixture resembles coarse meal. Add the unsalted butter and cut in or pulse until the dough begins to come together. Add the water and vanilla to the flour mixture; work it in with your fingers or with 2 pulses of the food processor. Gather the dough into a ball and let rest 10 minutes. Flatten the ball into a disk, wrap in plastic, and refrigerate at least 1 hour or overnight.
For the filling, soak the raisins in hot water to cover until plump, about 30 minutes; drain. Heat