For Crust, in large bowl with electric mixer, beat flour, sugar, margarine and salt until mixture resembles coarse crumbs. In 13 x 9-inch baking pan coated with nonstick cooking spray, firmly press crumbs into bottom and 1/4-inch up sides. Bake 15 minutes or until crust is golden brown.
For Filling, in large bowl, beat eggs, corn syrup, sugar, Peanut Butter, margarine and vanilla until well blended. Stir in peanuts. Evenly pour mixture over hot crust. Bake 20 minutes or until filling is firm around edges and slightly firm in center. On wire rack, cool completely. To serve, cut into bars.