Pecan Pie Surprise

1 box yellow cake mix
1/2 c melted margarine
1 c chopped pecans

FILLING
2/3 c cake mix
1/2 c brown sugar
1 1/2 c dark corn syrup
1 ts vanilla
3 eggs
1/2 c chopped pecans

Preheat over to 350. Grease bottom and sides of 13x9' pan. Reserve 2/3 c. cake mix for filling. In large bowl, combine mix, butter and pecans until crumbly . Press into pan. Bake 15-20 minutes or until brown.

Filling: Combine all ingredients except nuts; beat for 2 minutes. Pour over partially baked crust. Sprinkle with nuts. Return to oven and bake 30-35 minutes (until set) Cool. Cut into bars.