Reserve 2/3 cup dry cake mix for filling. In a large bowl combine remaining dry cake mix, butter and 1 egg. Mix until crumbly and press into a 13x9-inch greased pan.Bake at 350 degrees for 15 to 20 minutes untill golden brown.
Combine 2/3 cup dry cake mix, brown sugar, corn syrup, vanilla and 3 eggs. Beat at med. speed 2 minutes. Pour onto crust; Sprinkle pecans over filling. Return to oven and bake 30 minutes until filling is set. Cool. Cut into 36 bars.