Preheat oven to 400°F. Fit 1 pie crust into a 9-inch pie dish; chill while making filling.
In a saucepan, combine raisins, water, sugar, cinnamon, and salt. Simmer 5–7 minutes to plump raisins.
Whisk cornstarch with a few tablespoons cool water to form a smooth slurry. Stir into saucepan and simmer 1–2 minutes until glossy and thick.
Remove from heat. Stir in lemon juice, zest (optional), butter, and vanilla (optional).
Optional yolks: Temper yolks with a few spoonfuls of hot filling, whisk back into pot until blended.
Cool filling 10–15 minutes, then pour into chilled crust.
Top with second crust, crimp edges, and cut vents. Brush with egg wash if using.
Bake 20 minutes at 400°F, then reduce to 350°F and bake 25–35 minutes until crust is golden and filling looks set.
Cool at least 3 hours before slicing.