1. Preheat oven to 400°.
2. Weigh or lightly spoon flour into a dry measuring cup, and level with a knife. Combine flour, powdered sugar, cornstarch, and 1/8 teaspoon salt, stirring with a whisk. Cut in cream cheese and butter with a pastry blender or two knives until mixture resembles coarse meal. Transfer mixture to a 9-inch square metal baking pan coated with cooking spray; pat mixture evenly into pan. Bake at 400° for 18 minutes or until lightly browned.
3. Reduce oven temperature to 350°.
4. Combine maple syrup and next 3 ingredients (through eggs), stirring with a whisk. Stir in pine nuts. Pour syrup mixture over crust, spreading nuts evenly over top. Sprinkle with remaining 1/2 teaspoon salt. Bake at 350° for 25 minutes or until set. Cool. Cut into 25 squares.