2In a medium saucepan, mix together cornstarch, white sugar, salt, and nutmeg. Mix in sour cream. Add egg yolks, raisins, and lemon juice. Stir until thoroughly combined. Cook mixture over medium heat, stirring constantly, until mixture thickens and boils. Boil and stir 1 minute. Pour mixture into pastry shell.
3In a large glass or metal bowl, beat together egg whites and cream of tartar until foamy. Add brown sugar 1 tablespoon at a time, continuing to beat until whites are stiff and glossy. Beat in vanilla extract. Spread evenly over raisin filling, sealing meringue to crust edges.
4Bake in preheated oven for 10 minutes, until delicately browned.