Preheat oven to 350 degrees. Cream together cream cheese, egg, sugar and vanilla in mixing bowl. Beat until fluffy. Spread mixture on bottom of prepared pie shell. Sprinkle pecans over cream cheese layer. Beat remaining 3 eggs until well mixed but not foamy. Do not overbeat. Add corn syrup, sugar, vanilla, and salt. Mix well, pour over pecans. Bake at 350 degrees for 40 minutes or until nuts and lightly browned. Top will rise and sink as it cools. Serve warm or cold. May be frozen. Thaw at room temperature.